imo i would put them in 3 gal. pots now, lst them and veg for the next 2 weeks.
go to 12/12 and continue the lst for about another week. after a couple weeks of 12/12, the stretch should slow down, and you should have a nice even canopy of tops all tied horizontal. you dont want the tops to get too tall due to the penetration of the cfl's isnt very far.
if you have a good exh. fan at the top and a passive intake hole slightly larger than the exh. hole at the bottom, you should not need the plexiglass for cfl's. and you should be able to keep the door closed.
what is the temp of the air coming into the room?