Simple server-side mod that gives armor stands arms by default. The arms can also be toggled individually by shift-right-clicking an armor stand.
Download the latest release from here and put the .jar file into the mods folder in your Minecraft directory.
This mod is also available on Modrinth and CurseForge!
Development builds are available on GitHub Actions. These builds are not guaranteed to be stable and may contain bugs.
Thanks to rotgruengelb for providing the stonecutter-mod-template.