Yay, I was hoping there were some information about this out there! I've developed a few types of puzzles that I've been trying to come up with the puzzles by hand, and it's been really slow going.

I do agree that coming up with them by hand and designing puzzles with intent and possibly a theme is still probably for the best, but I think a hybrid approach, where you can use these generators to help give you ideas or starting points or fill in some gaps can be useful.