This is something I’ve wondered for the Gen-I Mark VI and Gen-II Mark I, what the hell are those things on the back of the armor that are cylinders or large bumps, they aren’t rockets as proven inside of the game and you still need jet packs, its not the thruster pack so what is it. It doesn’t seem to have any real purpose other than taking up space on the back of the armor.
MC used those to slow himself down in mid-air. I suppose the purpose is the same in other variations of the MJOLNIR.
They house the armor’s power supply, the standard EVA truster packs, and additional variant-specific equipment.