I don’t know if that might be informative:
I have tried the Mac Partha Gimp 2.10.18 and g’mic plugin build 2.9, surprisingly in the list of functions in g’mic plugin there is the Test section missing, as well as my .gmic user file! I have no idea how that can happen!
By the way, the plugin seems to be 2.9.0_pre#200302 and there are 390 filters. Are faves counted too?