[PaulDavisThe1st]

The extra hoop is having to start a2jmidi and have the ports not be as "integrated" into the JACK server ports as they could be.

By contrast, JACK1 contains a2jmidid as a builtin client, no extra work is needed. You just start JACK, all your MIDI devices are listed.

[lavabiopsy]

I have switched to Pipewire but last time I tried JACK2 there were tools that would auto-start a2jmidi for all available midi ports. This is trivial to do. If hotplug was a concern then someone could just write it to run based on udev triggers.