Add undo and redo shortcut buttons

Exactly! I just came across this thread because my son uses a 2-in-1 laptop to do art, plus he's lefthanded, so Ctrl+Z is very awkward for him to do with his (free) right hand (as the left hand is mousing). He would rather have buttons so that he doesn't have to use the menus while in tablet mode.

Some artists use tablet or like me I use 2 in 1 laptop so that I can draw with a pen and when rotating 360 degree or in a tablet there is no keyboard. You can ask yourself why fresco has that

Trust me, using the history panel is a disaster 

You mean actual buttons on screen? Why would that be any faster or more convenient than keyboard shortcuts?

The reason people use keyboard shortcuts extensively is precisely because it's much faster than navigating your cursor on screen. You can do it with your left hand while the right hand is still doing whatever it was doing - in other words in paralell instead of in sequence.

I don't think this is going to get much support.

Besides, there is the History panel for multiple steps.

I mean adding 2 buttons not the keyboard shortcuts 

There already is, ctrl-Z and alt-ctrl-Z. You can remap to anything you like in Edit > Keyboard Shortcuts.

Or check "legacy undo" in preferences to let ctrl+Z toggle. Also remappable.

Please