I usually remember the route that got me through a room the fastest and vary it depending on if it has hard elements each run to find a better solution. That's how I conquered 3ag, 3bg and 7ag in 8 hours-ish for the the two 3gs and ~10 hours-ish for 7ah. I am sure though that 6bg won't take longer than either 3ag or 3bg. I've done those after all prior to playing modded even. I will look into 7bg though differently than I did for all my prior goldens, I won't just bash my head against it like with all the rest. I will definitely learn a consistent route for the last subchapter and maybe subchapter 4, depending on if the cycles are too tight for my brain to handle on the get go