right here is your problem. Stop worrying so much about exactness. Interpret the rolls as it makes sense for the scene/moment. If you are wrong about it later, you can adjust it going forward.
On their charactersheet, I would have them list out the boons/banes they can do. If you don’t remember exactly what they do at different power levels, don’t sweat it, like I said.
Also, there is an app posted right here in the community forums that reads off of Heromuster, but keeps it stored on your phone so even if you don’t have internet, you still have it all on your phone. It syncs with it when it is online in case of any changes.