ah, yes, but qtractor will also do the evil thing and spit out some mmc
when it detects jack transport state has changed somehow outside its own
control. eg. press play in qjackctl => jack transport starts rolling =>
qtractor starts rolling too => qtractor sends out mmc play command and
probably jackmmcctl will do the same :)...
Actually, jackctlmmc only responds to the ports/programs that you've explicitly connected it to, so your scenario wouldn't cause problems as long as you only connected jackctlmmc to your external midi port. If you were foolish enough to manually connect it to external ports and every other application running on your system, then you would deserve whatever strange behavior you received :P
-- Alex