I wouldn't set that timer for 999. If someone logs in and forgets to log out, then you'll have to reset the system or wait almost 17 hours for the system to kick them out. 15 minutes seems to work for us. If you don't program anything for 15 minutes, you just have to log back in.
While I haven't done a PRI on an eMG80 (Summit), I have changed the CO Device Sequence Number. In your case, I would just leave it alone. Just put your PRI in Group 1, and everything else in another group.
