As the title reads, allowing for subelements (i.e. Curtain Wall mullions, stair structures, railing posts) to be used when filtering within GOs would be very, very nice though perhaps not as important as the other wish for improving GOs:
https://community.graphisoft.com/t5/Wishes-forum/More-override-options-for-Graphic-Overrides/td-p/33...
DIsclosure: I am using AC24. If this has already been addressed in AC25 then consider this solved.