At the Hedges of Time did fake undo in puzzlescript, but the code is super complex - thinking about it, idk if Tres Undos would be doable in puzzlescript, even with more buttons & being able to hijack the undo button.
I've just remembered that there's a cleaner codebase for the multi undo system: here is the source code for this game, which is basically Breakout but with white/orange/red bricks. If you were to make Tres Undos with multiple players, it might be easier to remake it from scratch taking this as a base, than trying to modify Tres Undos directly.
My discord tag is knexator#4865, feel free to DM me.