I do prestige and as far as I can in masters. I can finish prestige without gold and had a level up so was able to get through 13/20 as well. I just don't really care about xp gain anymore. Main reason I do them is to stockpile energy refills but those have been cut down to one per goal chain. Just in case they bring back fltq want to stockpile them.
How much is your + to energy regen?
No, it's not what you think. It's much, much worse!