Definitely a brain fart on my part here - Jack DOES
handle
routing MIDI, as long as you click on the MIDI tab in
Qjackctl!
Jack does not handle the MIDI data, but qjackctl does include
the possibility to drive the ALSA sequencer from within its
UI.
I for myself would be very pleased if every soundapp which
requires MIDI input had the possibility to select the MIDI
input from within the UI, but most do not have such a popup
or similar.
Best regards
ce