[Active Sensing]
You said that you "need lossless JACK MIDI networking", but not why you
need networking at all. You might have a good reason, I'm just curious.
For what purpose do you need an _additional_ network?
Btw. I have no experiences with MIDI over an additional network, but
regarding the missing note-off issue, a standard MIDI "network" (= MIDI
not over an additional network) has got the "Active Sense" (0xFE)
message, that could workaround some (not all) missing note-off issues.