If a frame is mere than 2/3 capped and there isn't fresh nectar coming in from a honey flow, the open cells are more than likely to be ripe enough for extraction. If you have any doubts about it's ripeness, shaking the frame firmly over the hive while held flat, is the way to test it. If no honey shakes out, than you're okay. If drops of honey come out from the cells, than you've got unripe honey and best think twice about using the frames for exraction.
If you don't store the empty frames in the hive, over the inner cover, and you have sprayed them with BT, it is still best to place the supers with the frames in a large plastic bag as extra insurance against posssible moth infestations. The moths can be very determined and if they get in and lay eggs, even though the larvae will die young, they can still cause some damage before they die.