It's agreed that there are lots of ways to invoke the "UNDO" command.
But every one of them requires the user to reach out and touch either the keyboard or the screen to cause "UNDO" to happen. This is an unnecessary and disruptive extra action.
The original request in this string of having an on-screen button for UNDO is valid and useful for two reasons, and I am joining in on this request.
[1] Having an UNDO button allows the user to keep the flow going without having to leave the mouse, and/or execute a command from a dropdown menu, and/or bring the other hand into play. This makes it fast and easy to execute this very frequent command. This is a win.
[2] It's such a win that most every program out there has an UNDO button. So it's a glaring deficiency by it's absence in the Affinity programs.
I'll submit that this same "winning" feature would also be the presence of a "SAVE" button on the Toolbar. Again, every other program has this, for the same good reason.
At the very least, it seems that it could be possible that these user interface changes could be made possible by including them in the "Customize Toolbar" dialog box.
Again, I'll include my vote for this feature.
Cheers,
RB