Intel Macs:
SwitchResX 4 versions that were compatible with macOS Catalina are also compatible with BigSur
Some visual glitches may occur on these versions however, due to visual changes in BigSur.
Version 4.11 is tested on BigSur and should correct these interface errors, and bring better BigSur interface support.

Apple Silicon Macs:
Please see the specific FAQ for Apple Silicon Macs.


For all Macs:
Interlaced resolutions were removed from macOS video drivers on all Macs, Intel or Apple Silicon, with macOS 11.0
If you absolutely require interlaced resolutions, stay on macOS Catalina with your Intel Mac.
That also means that no Apple Silicon can (actually) support interlaced resolutions, from what I know.