Please change the button presses to Rewind/Fast-Forward. 10 seconds is good for now, and maybe a user-selectable setting in the future (5s, 10s, etc. this feature is very common in audiobook apps)
Currently, button pressing is linked to previous/next track functionality. I know that button pressing makes it easier to navigate tracks, but we already have the ability to do that by turning the right knob. So, previous/next can be done in 2 different ways, but rewind/fast-forward can't be done at all?
I would really like the ability to skip back a few seconds. Chapters can be quite long (~10m) and if you miss something, you need to re-listen to the whole track.
Some users might prefer this idea, and others might prefer the current behavior, so make it a settings option to choose. E.g. For a toddler, I'd probably want button pressing to navigate as previous/next through songs, but for older kids they'd like rewind behavior during stories.