Scramble is nice, to redo a puzzle one likes.
I would hope that there is a funtion that changes the "numbers" during a scramble.
What I mean is, if I scramble a favorite puzzle (with an x-wing on 5s) I would prefer that it was no longer on 5s.
So, combine number swap with scramble (my choice) or make it an option, please.
Scramble
Brilliant!
Great work Ruud, you had it figured from the get-go.