diff --git a/ghc/Categorifier/GHC/Driver.hs b/ghc/Categorifier/GHC/Driver.hs
index 1f44e0ea..b70e4ebf 100644
--- a/ghc/Categorifier/GHC/Driver.hs
+++ b/ghc/Categorifier/GHC/Driver.hs
@@ -1,10 +1,14 @@
 {-# LANGUAGE CPP #-}
+{-# LANGUAGE PartialTypeSignatures #-}
+{-# OPTIONS_GHC -Wno-partial-type-signatures #-}
 
 module Categorifier.GHC.Driver
   ( module DynFlags,
     module HscTypes,
     module Outputable,
     module Plugins,
+    defaultPurePlugin,
+    pureDynflagsAndCorePlugin,
   )
 where
 
@@ -28,3 +32,32 @@ import HscTypes hiding (InteractiveContext (..), InteractiveImport (..), ModGuts
 import Outputable hiding (Outputable (..), renderWithStyle)
 import Plugins
 #endif
+
+-- | Like `defaultPlugin`, but specifies that the plugin is pure (when GHC allows).
+defaultPurePlugin :: Plugin
+#if MIN_VERSION_ghc(8, 6, 0)
+defaultPurePlugin = defaultPlugin {pluginRecompile = purePlugin}
+#else
+defaultPurePlugin = defaultPlugin
+#endif
+
+-- | Builds a pure plugin that has both `DynFlags` and `Core` components. Prior to GHC 8.10, the
+--  `DynFlags` component will be ignored and so the flags must be manually configured to match.
+pureDynflagsAndCorePlugin ::
+  ([CommandLineOption] -> DynFlags -> IO DynFlags) ->
+  -- | @([CommandLineOption] -> [CoreToDo] -> CoreM [CoreToDo])@, but skipped to avoid import issues
+  _ ->
+  Plugin
+#if MIN_VERSION_ghc(9, 2, 0)
+pureDynflagsAndCorePlugin dynflags core =
+  defaultPurePlugin
+    { driverPlugin =
+        \opts hsc -> (\newFlags -> hsc {hsc_dflags = newFlags}) <$> dynflags opts (hsc_dflags hsc),
+      installCoreToDos = core
+    }
+#elif MIN_VERSION_ghc(8, 10, 0)
+pureDynflagsAndCorePlugin dynflags core =
+  defaultPurePlugin {dynflagsPlugin = dynflags, installCoreToDos = core}
+#else
+pureDynflagsAndCorePlugin _ core = defaultPurePlugin {installCoreToDos = core}
+#endif
diff --git a/ghc/categorifier-ghc.cabal b/ghc/categorifier-ghc.cabal
index 31f1fc9c..695d8557 100644
--- a/ghc/categorifier-ghc.cabal
+++ b/ghc/categorifier-ghc.cabal
@@ -55,7 +55,6 @@ library
       Paths_categorifier_ghc
   ghc-options:
     -O2
-    -fignore-interface-pragmas
   build-depends:
     , PyF ^>=0.9.0 || ^>=0.10.0 || ^>=0.11.0
     , bytestring ^>=0.10.9 || ^>=0.11.0
diff --git a/integrations/adjunctions/integration-test/categorifier-adjunctions-integration-test.cabal b/integrations/adjunctions/integration-test/categorifier-adjunctions-integration-test.cabal
index a6cf1730..17869d42 100644
--- a/integrations/adjunctions/integration-test/categorifier-adjunctions-integration-test.cabal
+++ b/integrations/adjunctions/integration-test/categorifier-adjunctions-integration-test.cabal
@@ -86,4 +86,3 @@ test-suite adjunctions-hierarchy-optimized
   main-is: Adjunctions/Main.hs
   ghc-options:
     -O2
-    -fignore-interface-pragmas
diff --git a/integrations/categories/integration-test/categorifier-categories-integration-test.cabal b/integrations/categories/integration-test/categorifier-categories-integration-test.cabal
index 4e03ef9f..8e9bbdf1 100644
--- a/integrations/categories/integration-test/categorifier-categories-integration-test.cabal
+++ b/integrations/categories/integration-test/categorifier-categories-integration-test.cabal
@@ -78,4 +78,3 @@ test-suite categories-hierarchy-optimized
   main-is: Categories/Main.hs
   ghc-options:
     -O2
-    -fignore-interface-pragmas
diff --git a/integrations/concat-extensions/integration-test/categorifier-concat-extensions-integration-test.cabal b/integrations/concat-extensions/integration-test/categorifier-concat-extensions-integration-test.cabal
index f78d9282..a5158762 100644
--- a/integrations/concat-extensions/integration-test/categorifier-concat-extensions-integration-test.cabal
+++ b/integrations/concat-extensions/integration-test/categorifier-concat-extensions-integration-test.cabal
@@ -86,4 +86,3 @@ test-suite concat-extensions-hierarchy-optimized
   main-is: ConCatExtensions/Main.hs
   ghc-options:
     -O2
-    -fignore-interface-pragmas
diff --git a/integrations/concat/integration-test/categorifier-concat-integration-test.cabal b/integrations/concat/integration-test/categorifier-concat-integration-test.cabal
index 0ad027db..47258c86 100644
--- a/integrations/concat/integration-test/categorifier-concat-integration-test.cabal
+++ b/integrations/concat/integration-test/categorifier-concat-integration-test.cabal
@@ -89,7 +89,6 @@ test-suite concat-class-hierarchy-optimized
   main-is: ConCat/Main.hs
   ghc-options:
     -O2
-    -fignore-interface-pragmas
 
 test-suite concat-function-hierarchy
   import: hierarchy-tests
@@ -104,4 +103,3 @@ test-suite concat-function-hierarchy-optimized
   main-is: ConCat/Main.hs
   ghc-options:
     -O2
-    -fignore-interface-pragmas
diff --git a/integrations/ghc-bignum/integration-test/categorifier-ghc-bignum-integration-test.cabal b/integrations/ghc-bignum/integration-test/categorifier-ghc-bignum-integration-test.cabal
index b54ccd98..a0adac5c 100644
--- a/integrations/ghc-bignum/integration-test/categorifier-ghc-bignum-integration-test.cabal
+++ b/integrations/ghc-bignum/integration-test/categorifier-ghc-bignum-integration-test.cabal
@@ -89,4 +89,3 @@ test-suite ghc-bignum-hierarchy-optimized
   main-is: GhcBignum/Main.hs
   ghc-options:
     -O2
-    -fignore-interface-pragmas
diff --git a/integrations/linear-base/integration-test/categorifier-linear-base-integration-test.cabal b/integrations/linear-base/integration-test/categorifier-linear-base-integration-test.cabal
index e4abf99a..0e984e88 100644
--- a/integrations/linear-base/integration-test/categorifier-linear-base-integration-test.cabal
+++ b/integrations/linear-base/integration-test/categorifier-linear-base-integration-test.cabal
@@ -91,4 +91,3 @@ test-suite linear-base-hierarchy-optimized
   main-is: LinearBase/Main.hs
   ghc-options:
     -O2
-    -fignore-interface-pragmas
diff --git a/integrations/unconcat/integration-test/categorifier-unconcat-integration-test.cabal b/integrations/unconcat/integration-test/categorifier-unconcat-integration-test.cabal
index 5e5d6330..d81d9bd0 100644
--- a/integrations/unconcat/integration-test/categorifier-unconcat-integration-test.cabal
+++ b/integrations/unconcat/integration-test/categorifier-unconcat-integration-test.cabal
@@ -84,4 +84,3 @@ test-suite unconcat-hierarchy-optimized
   main-is: UnconCat/Main.hs
   ghc-options:
     -O2
-    -fignore-interface-pragmas
diff --git a/integrations/vec/integration-test/categorifier-vec-integration-test.cabal b/integrations/vec/integration-test/categorifier-vec-integration-test.cabal
index ef5bafda..8ea22f77 100644
--- a/integrations/vec/integration-test/categorifier-vec-integration-test.cabal
+++ b/integrations/vec/integration-test/categorifier-vec-integration-test.cabal
@@ -93,4 +93,3 @@ test-suite vec-hierarchy-optimized
   main-is: Vec/Main.hs
   ghc-options:
     -O2
-    -fignore-interface-pragmas
diff --git a/plugin-test/categorifier-plugin-test.cabal b/plugin-test/categorifier-plugin-test.cabal
index a44984c2..90005de0 100644
--- a/plugin-test/categorifier-plugin-test.cabal
+++ b/plugin-test/categorifier-plugin-test.cabal
@@ -110,4 +110,3 @@ test-suite base-hierarchy-optimized
   main-is: Base/Main.hs
   ghc-options:
     -O2
-    -fignore-interface-pragmas
diff --git a/plugin/Categorifier.hs b/plugin/Categorifier.hs
index 101d9414..c6503d9c 100644
--- a/plugin/Categorifier.hs
+++ b/plugin/Categorifier.hs
@@ -14,6 +14,7 @@ where
 import Categorifier.CommandLineOptions (OptionGroup, partitionOptions)
 import Categorifier.Common.IO.Exception (throwIOAsException)
 import qualified Categorifier.Core
+import qualified Categorifier.DynFlags
 import qualified Categorifier.GHC.Core as GhcPlugins
 import qualified Categorifier.GHC.Driver as GhcPlugins
 import Control.Applicative (liftA2)
@@ -30,15 +31,14 @@ import PyF (fmt)
 --   for more information.
 plugin :: GhcPlugins.Plugin
 plugin =
-  GhcPlugins.defaultPlugin
-    { GhcPlugins.installCoreToDos =
-        \opts ->
-          join
-            . GhcPlugins.liftIO
-            . liftA2 Categorifier.Core.install (partitionOptions' opts)
-            . pure,
-      GhcPlugins.pluginRecompile = GhcPlugins.flagRecompile
-    }
+  GhcPlugins.pureDynflagsAndCorePlugin
+    (\_opts -> pure . Categorifier.DynFlags.plugin)
+    ( \opts ->
+        join
+          . GhcPlugins.liftIO
+          . liftA2 Categorifier.Core.install (partitionOptions' opts)
+          . pure
+    )
 
 partitionOptions' :: [GhcPlugins.CommandLineOption] -> IO (Map OptionGroup [Text])
 partitionOptions' opts =
diff --git a/plugin/Categorifier/Core/ErrorHandling.hs b/plugin/Categorifier/Core/ErrorHandling.hs
index b31a2e55..b8f20408 100644
--- a/plugin/Categorifier/Core/ErrorHandling.hs
+++ b/plugin/Categorifier/Core/ErrorHandling.hs
@@ -232,11 +232,9 @@ required by {showE expr}.|]
    `inlinable` pragma to the definition or compiling with
    `-fexpose-all-unfoldings` to make _every_ operation inlinable. It's also
     important that the module containing the call to `categorify` is compiled
-    with `-fno-ignore-interface-pragmas` (also implied by `-O`). If the
-    unfolding that's missing is for `$j` (GHC-internal join points), you may
-    need to bump `-funfolding-creation-threshold` on the modules you're
-    depending on. If there is still no unfolding available, please file an issue
-    against the plugin.|]
+    with `-fno-ignore-interface-pragmas` (also implied by `-O` and enabled
+    automatically on GHC 8.10.1 or later). If there is still no unfolding
+    available, please file an issue against the plugin.|]
             Plugins.BootUnfolding ->
               [fmt|
     The identifier is defined in an hi-boot file, so can't be inlined.|]
diff --git a/plugin/Categorifier/DynFlags.hs b/plugin/Categorifier/DynFlags.hs
new file mode 100644
index 00000000..aebd2ba7
--- /dev/null
+++ b/plugin/Categorifier/DynFlags.hs
@@ -0,0 +1,20 @@
+module Categorifier.DynFlags
+  ( plugin,
+  )
+where
+
+import qualified Categorifier.GHC.Driver as GHC
+
+plugin :: GHC.DynFlags -> GHC.DynFlags
+plugin = setUpDynFlags
+
+-- | This sets up flags that allow the plugin to do what it needs to.
+--
+--   For a compiler that doesn't support this plugin (before GHC 8.10), the following GHC options
+--   approximate it:
+--
+--  [@-fno-ignore-interface-pragmas@]: Ensures we can inline definitions that we don't know how to
+--                                     interpret directly to the target category. This flag is also
+--                                     implied by @-O@ and @-O2@.
+setUpDynFlags :: GHC.DynFlags -> GHC.DynFlags
+setUpDynFlags = GHC.unSetGeneralFlag' GHC.Opt_IgnoreInterfacePragmas
diff --git a/plugin/README.md b/plugin/README.md
index 753985e6..0eed845d 100644
--- a/plugin/README.md
+++ b/plugin/README.md
@@ -11,8 +11,9 @@ directly, as well as ones that are depended on (transitively) by the ones that u
 
 ### targets you want to use `categorify` in
 
-- enable the plugin with `-fplugin=Categorifier`,
-- ensure inlining is available with `-fno-ignore-interface-pragmas` (implied by `-O` or `-O2`), and
+- enable the plugin with `-fplugin=Categorifier`;
+- if you are using a version of GHC older than 8.10.1, use the flags described in
+  [Categorifier.DynFlags](./Categorifier/DynFlags.hs); and
 - import `Categorifier.Categorify` to make `categorify` available (you must import the _entire_ module,
   but it may be qualified).
 
@@ -32,26 +33,6 @@ directly, as well as ones that are depended on (transitively) by the ones that u
 - define `Categorifier.HasRep` instances for any types that you use in a converted function (the plugin
   will tell you if you are missing any when you try to convert)
 
-### fine-tuning inlining sizes
-
-It can be difficult to find a reasonable setting for the various inlining thresholds. This attempts
-to lay out an approach for identifying one.
-
-There are two significant GHC flags for adjusting inlining, `-funfolding-creation-threshold` and
-`-funfolding-use-threshold`. They allow you to set an upper bound on the "size" of unfoldings that
-will be considered for inlining.
-
-1. set the `creation` (globally) threshold high, say `10000`;
-2. test to see if the inlining issue goes away (if so, skip to step 5);
-3. set the `use` (in `categorify` modules) threshold to match the `creation` threshold;
-4. do a binary search on the `use` thresholds to minimize them as much as possible;
-5. do a binary search on the `creation` thresholds to minimize them as much as possible (the lower
-   bound here is probably the minimum of 750 (the default) and the `use` threshold).
-
-If either if these values is too small, you'll end up with errors complaining that some definition
-couldn't be inlined. If they're too big, you'll get errors about "simplifier ticks exhausted" (in
-which case, you can bump `-fsimpl-tick-factor`) and things will take a lot longer to compile.
-
 ### defining `HasRep` instances
 
 You should use `Categorifier.Client.deriveHasRep` for all `HasRep` instances. However, for
@@ -146,9 +127,10 @@ This is ostensibly a more correct approach, given the way GHC is structured, but
 
 There are a bunch of modules, this calls out the most important ones when diving in.
 
-- [`Categorifier`](./Categorifier.hs) - this is the entrypoint of the plugin, everything that hooks into
-  GHC starts from here;
-- [`Categorifier.Core.Categorify`](./Categorifier/Core/Categorify.hs) - the high-level logic of the
+- [Categorifier](./Categorifier.hs) - this is the entrypoint of the plugin, everything that hooks into
+  GHC starts from here, with there being three immediate subcomponents: command-line option
+  handling, `DynFlags` settings, and the Core pass;
+- [Categorifier.Core.Categorify](./Categorifier/Core/Categorify.hs) - the high-level logic of the
   categorical transformation as described in Conal's paper, it tries to define as clearly as
   possible the mapping from **Hask** to abstract categories;
 - [`Categorifier.Hierarchy`](./Categorifier/Hierarchy.hs) - the mappings from abstract
diff --git a/plugin/categorifier-plugin.cabal b/plugin/categorifier-plugin.cabal
index 2666555e..610f3f36 100644
--- a/plugin/categorifier-plugin.cabal
+++ b/plugin/categorifier-plugin.cabal
@@ -53,6 +53,7 @@ library
       -- __TODO__: move ...PrimOp to other-modules
       Categorifier.Core.PrimOp
       Categorifier.Core.Types
+      Categorifier.DynFlags
       Categorifier.Hierarchy
   other-modules:
       Categorifier.Benchmark
@@ -67,7 +68,6 @@ library
       Paths_categorifier_plugin
   ghc-options:
     -O2
-    -fignore-interface-pragmas
   build-depends:
     , PyF ^>=0.9.0 || ^>=0.10.0 || ^>=0.11.0
     , barbies ^>=2.0.1
diff --git a/th/categorifier-th.cabal b/th/categorifier-th.cabal
index 409ecc13..13f238e7 100644
--- a/th/categorifier-th.cabal
+++ b/th/categorifier-th.cabal
@@ -45,7 +45,6 @@ library
       Paths_categorifier_th
   ghc-options:
     -O2
-    -fignore-interface-pragmas
   build-depends:
     , PyF ^>=0.9.0 || ^>=0.10.0 || ^>=0.11.0
     , categorifier-common