Making an editor, at least a basic one, is a good idea. But I would do that as part of version 2. The existing puzzles were simple enough that I could design them on paper and manually type each definition into puzzle_boards.js
You're right it doesn't take full advantage of the F shape. I just needed a set of four symbols (in this case it's the four rotations of 'F'), each of which transform into a new symbol when reflected over the northeast diagonal. I do hope to make more puzzles with that symbol set in the future. Edit: In the second version there will be multiple options to pick from.
