This is a thumbs up for GigPerformer and how well it works with ‘MIDI Learn’ in the Rig Manager.
My home 88 USB keyboard didn’t work anymore, so I replaced it with a very old Korg N264 keyboard.
Since my music rack only has one MIDI input (for the Behringer FCB1010 pedal), I connected the Korg N264 to the Behringer pedal’s MIDI In, and its built in MIDI merge sends both MIDI signals from the Korg and Behringer to Gig Performer.
I ‘relearnt’ the FCB1010 and the Korg (to replace my 88 keyboard), pressed apply/save, and everything works again. Even despite this is not a trivial connection.