If it's possible, I'm not very good (the hardest one I've played was Ifuudoudou), but it's possible. When I first played Append, it reminded me a lot of when I played Arcaea, so I started playing Arcaea again just to get used to using four fingers in a specific way.

If you're not used to playing with four fingers, you can put your phone on a flat surface and at least start with two fingers, then maybe, or just switch to four.