- Pressing 1, 2 and 3 toggles between vertex, edge and face selection in edit mode. This is used all the time.
- Pressing 1, 2 and 3 isolates a collection in object mode. This mistake is done all the time…
If you have a lot of collections, some visible, some hidden, accidentally pressing a number key while in object mode wastes a lot of your time.
Pressing 1 twice in object mode should return the visibility state to where it was before pressing the button.
(Note: This is very similar to how in 2.79 you could contol click to isolate a hierarchy in the outliner, and then click again to revert to the previous visibility state. This was initially removed in 2.8 and replaced with a destructive click, only to be brought back to a toggle after users complained.)