Assign keys by relative pitch / harmonic function

Apologies if this already available somehow, but I’d like to be able to assign MIDI keys by harmonic function (i.e., Roman numeral) as opposed to absolute pitch class. I was hoping I could use something like a Korg Nanopad to play progressions with the tonic always on the first pad, the subdominant on the fourth pad, and so on. Thanks.

Thanks for the suggestion, it is something we have considered and it is on the roadmap, maybe a Scaler 2.5 thing