My group and I experience this today also. We got to the last room and after two attempts, one of our members got disconnected or just logged off for whatever reason. We waited a bit and decided to send someone up to look for more help. They ended up not being able to get back down. Please change it so that members who leave for whatever reason (sometimes people forget things like hypos or borg weapons) should be able to get back to the instance provided at least one person from the group is still there.
As long as the group stays together and the leader doesn't change, this shouldn't be an issue. Needless to say, none of us wanted to redo the hour grind through to the last boss just for the purple drop we were trying to get for the new guy.
I do like that you get a Mark of Valor for the gateway of the miniboss now though! That's a nice improvement. Even if you don't get the boss down, you still get a little more incentive.
Actually the points for defeating the boss is new and not knew. Originally you did get points for defeating the mini bosses, but they had to move them all 5 points with Rebecca. Its just that they spread the points out once again. 1 for the Tactical, one for Ogden, and 3 for Rebecca.
BTW, to add. I noticed Cryptic fixed the Wall Exploit in Rebecca's lair, but they forgot the NW corner. That console is still partly behind the wall.