One thing we've done in ChimeraX is standardize on using integers instead of enum values as they exist in PyQt6 which poses a challenge because we're still thinking about whether we want to use that or PySide6.

We have two utility functions, qt_enum_as_int and qt_int_as_enum, to help us achieve the flexibility we need. For other packages (PyQt5, pyside2, pyside6) that don't use enums, we test whether the input is a subclass of enum.Enum and return the input if it isn't.

Does that sound like something that would be useful in compat.py?