1st idea: I don't know, it just came in my brain but what if we had pb (puzzle battle) have different types of puzzle battle each focusing on a type of category of things (Ex. Pins, forks, laddering, pawn promotion etc.) I feel like puzzle battle is boring and implementing would make this actually fun. Also it might also help me learn how to play better XD.
2nd idea: I really hate the fact there is only one time control. Maybe you could add more time controls like 1 minute or 5 minutes. Maybe you could even add one without a time limit and who ever fails 3 like normal pb you lose. (By the way, if people afk they will have 1 minute to do the puzzle before it counts as auto resign. Also like normal pb, if someone gets 3 wrong and the other person has a higher amount of points, they automatically win.)
Last idea: What if you had a menu that allowed you to adjust the difficulty of the puzzles. (If you don't know what I mean, puzzles are given an assigned difficulty, so what if that is in pb with the harder difficulties, they give more rating if you win and lose just slightly less rating when you lose based on the difficulty.)
Thank you and I would love it if I could see this in Chess.com