Got it! 
GitHub - neon-age/Unify: Fix Unity.
Also included my Material Inspector save fix .
Right now injection points are patched using Harmony.
It is done for:
EditorUtility.DisplayPopupMenu (Project browser)
EditorUtility.DisplayCustomMenuWithSeparators (all GenericMenus, including Enum fields and Hierarchy)
(there’s also GenericMenu.DropDown which does not include Enums)
GenericMenu.ObjectContextDropDown (Inspector components + material header)
Also used Unity.InternalAPIEngineBridge assembly for a few internal APIs.
Styling is a bit broken, but otherwise everything seems to function in order (haven’t tested thoroughly tho).
