With that said Kaen, I've not tried with EMU but I imagine it's not any different. I would load all my toons on test with the test MQ2 going, then after all toons were logged into test, I would right click the MQ2 icon in tray and exit.
Once exited I would then load up MQ2 for live and log in all my characters for live.
In this way I was able to use MQ2 on both at the same time.
I imagine it's the same for EMU
But again, kaen is not wrong. Also, if for some reason you crash on EMU, you've already closed the MQ2 down for that and loading a new toon back in won't load MQ2 unless you then close it in the tray to get rid of the live and switch back to EMU
FYSA, I can't find the post but they have the ability to check multiple clients from the same IP. Sounded like GMs use that to pop around to see if folks are botting. Honestly, my view is since they specifically request people not box there so I wouldn't box there.
I've not tried this but given the memory offsets in the P99 Green will differ (as will the version check), you should be able to run MQ2 Live without issue while logging into P99 Green. The MQ2 client will squawk about a version mismatch and then not work with the P99 client but should still be running...
I assume it would work the same as test and live. I often log in a toon to live via a separate instance install of EQ without mq2, while I have my test team running MQ2 over there. Never have a problem. I do get the version mismatch on the live instance when it starts up, but it logs in and runs with no problem...just no MQ2 over there.