New puzzle mode named custom puzzles,that let you change the rating of your puzzles,from 600 to 4000

I think that will greatly improve the puzzle experience. Some times you like to play some easy puzzle and some time hard ones, it would be nice to have this future in the site and the mobile app.

I agree with that. Lichess only gives us 6 puzzle modes: -600, -300, normal, +300, and +600. It would really make Lichess players more happy.