level selection and undo

[Dohi64]

would it be possible to improve level selection? adding a scrollbar and mousewheel scrolling, or even expaning it to the main area to make selecting levels quicker.

and how about making the right mouse button and/or the mousewheel function as undo as well? I thought one of them was already a thing but apparently it isn't (last played 2 months ago, came back now for the new puzzles).