Only three presets for radio stations and playlists is really a hard downside in usability of an otherwise excellent and high quality device. Here are two possible solutions which won’t interfere with other buttons and keep the simplicity of the remote.
Use longpush preset button to access 2nd layer (1/4, 2/5, 3/6) - limited to 6 presets and not completely satisfying
Use longpush preset buttons to toggle between ‚standard-mode‘ and ‚scroll-mode‘. In scroll-mode use <1> to scroll down, <3> for up and <2> for enter (if necessary)
Current preset longpush store-function on remote is quite useless since you need the app to find and select the radio station or playlist you want to store. So it can be abandoned.
If current usage must not be changed, then please make enhanced preset method selectable in the preferences menu.
This really is a long-term-annoying issue, which made me think to change to another receiver (I prefer remote to app control).