“MIDI patchbay lets you hook up your various pieces of MIDI software and hardware and pass MIDI data between them, applying assorted filters on the way. Things like key splits, MIDI channel remapping, transposition, etc. are simple.
If you want to tinker, you can find the source code on GitHub.
Tested and working in MacOs Monterey 12.1”
Source : notahat.com
Thanks it works on 2015 MacBookPro with BigSur 11.7.6.!