This app hits a lot of the Pocket Operator type features. I really like how you've laid everything out. Once you get over the learning curve of the controls, there is quite a bit of functionality here and it looks like a really promising app.
I'm going to try to transpose a song and make a pattern for real, but it will take me a little bit as i'm not all that musical
Some control function ideas:
1. on the synth/pattern & drum/pattern screens. Maybe hold "A" + DPAD left, right make it jump by an octave instead of having to up, down note by note to get to where you want to be. (same on BPM for both drums and pattern jump by BPM 5 or 10 with "A" + DPAD left, right and keep .1 with up/down)
2. the crank up or down controls to move between home screen and down a menu seems to take more cranking that I would expect. On my app, I built in a mechanism to "screen swipe" (although mine works with the dpad, the x value to swipe in/out could be tied to the crank change to make it work similarly). perhaps code this mechanic to slide the screen in via the crank to it is more obvious what the crank is doing as you transition a screen? (see example here (although the gif is way slower than actual device takes 250ms....if you want the source i can share it w/ you, just msg me on the PD forum): https://devforum.play.date/t/sawtooth-a-chiptune-music-player-devlog/13344
Just a heads up, there is already a Playdate game called Yacht for PD which is a Yahtzee type dice game: https://nkorth.itch.io/yacht