Currently there are many aspects which have been grouped under the SETTINGS button which I think conceptually and practically belong and would be better separated out elsewhere - chiefly such drum style metronome and performance.
Typical in apps - “Settings” or “preferences” menus or buttons tend to be used for things that one is not likely to change much from session to session. So can be hid away under such a button and the complexity of access isn’t much of an issue.
But Drum style, metronome and record performance - are aspects that will be used very frequently so need as few “clicks” to access them.
So maybe add a new button for PERFORMANCE.
And for drum style and metronome options - how about bringing up the options for either of those simply by holding down the DRUM or METRONOME button for either for more than say a second or more in order to invoke. Obviously one wants to avoid cluttering that lovely minimal interface but access to these oft-used features need to be made less fiddly and quicker.