For your first question about triggering with ports open (or close). That is not currently supported however I think it is an interesting request so will request that as an enhancement for future versions.
Queing output is also currently not supported yet it might be a bit dangerous to cue up too many messages as it could bog MT Pro buffers down. I'll also request as an enhancement, however.
I could envision seeing a translator like this:
Incoming trigger: port xxx opens
Outgoing action : (some SysEx initialization stream) to port xxx
For now, you would need to just periodically try and send data to a given port or, trigger the outgoing message by an incoming message from that port (once it opens).
Steve Caldwell Bome Q and A Moderator and Independent Bome Consultant/Specialist bome@sniz.biz