(On the left, the theme working properly. On the right, what most title bars look like.)
When attempting to use XFCE's experimental Wayland session, most of the XFWM4 titlebars don't show up properly when attempting to use labwc. So far, my attempts at fixing this issue, ranging from trying to force the theme with gtk-config, attempting to set a similar theme with labwc-tweaks, and scouring the relevant XFCE forums did not bring anything fruitful.
One thing I should note though, only the titlebars don't work; The rest of the theme works perfectly fine, save for the desktop wallpaper(s) being stuck at their defaults. The tool XFCE uses to change said wallapapers don't work on Wayland XFCE.