I'm only a few days away from completing stage 6 of AM 5.0 and would like to know what is the optimal way to use the stage 7 refresher before I use another sub (hopefully BAMM 2.0 when it's released)
Stage 7 is intended as just that - a refresher. If you are planning to use BAMM 2.0, you won't have time to need to use it, unless you decide to use it as a 7th stage. I suggest that you won't need a refresher for at least a couple months.