http://beyond.divinedivinity.net/help/act4_academy_l1.htm

Talking about the key at 23 to exit at 27 to the maintenance tunnels 1.

http://beyond.divinedivinity.net/help/act4_pipes_l1.htm

talking about the levers at 2, 13, 18, 22 to get to the exit at 28 - ascend to get to the teleporter to Academy lvl 2.

Exit at 11 is only possible with Tax's key => after you have triggered the 2nd summoning quest.

I will copy a 1.42 game into 1.44 now and see, if the BF exit prob still persists.