How to get 2.79 Undo system in 2.9?

Maybe this is unpopular but I need the Undo to be like in 2.79, because it allowed me to make experimental moves then undo them all by undoing in object mode once.
Meaning, I was using object mode like a “checkpoint”, and it was very useful.
The lack of this feature makes me reopen the file often, to undo many things together (especially when undoing means undoing some progressive selections with crtl +, that wastes all the Undo history steps).

I tried to untick “Global Undo”, saved preferences and closed/reopened Blender, but it doesn’t work and it behaves the same, it toggles between object mode and edit mode between steps… Instead I want that if I am in Object mode, I keep undoing the object mode, not entering in Edit steps.

Else: is there any plugin to have this again? Or a side feature to get these “checkpoints” again instead of having to save and reopen the file…