Currently MIDI Learn function of External Devices only works with MIDI CC (Control Change) so only faders/encoders can be assigned to a particular function in Studio One. However most MIDI controllers use MIDI notes for buttons, so users are forced to convert MIDI Notes to CC in 3rd party software in order for Learn function learn buttons.
I use X-touch, it's Mackie Control is limited in Studio One so MIDI Learning is imperative. Other controllers (including Faderport) don't provide functionality that I need for live mixing.
Please add MIDI Notes to MIDI Learn: exclusion of MIDI Notes is a surprise and doesn't make sense. Full MIDI Learning rather than CC only - would make Studio One move versatile.