There's already so much gain the Crunchbox has on tap, I find it hard to believe you'd need something to goose that! Once gain is anything more than 1 o'clock, I've found that other pedals before it don't add much to the gain noticably - just noise. Stacked with a Hotcake (on low drive settings), there's hardly any difference in gain or tone. Stacked with a Keeley TS9DX Flexi on medium gain, it's just noisy and the distortion characteristic sounds slightly fuzzy. You may have better luck with a booster just for a volume boost if you're taking solos, rather than another dirt pedal. Another dirt pedal's drive will just colour the Crunchbox's sound - but maybe you'll find something that complements it. So far I've found the Crunchbox sounds best on its own, no trouble or loss of anything switching from rhythm to lead as it sounds great for both applications.
I haven't tried stacking the Sahasrara with the Crunch Box as they're on different boards. I can try that tomorrow if you like.