I had the idea that since over flow power happens from bases and tethers, if you had a qt rtg on your pack, could it transfer power back to the base when your packs battery is charged? Especially at night, I think it would just be a nice feature to not have to take it off and slot it into your base. Same for rovers.
Speaking of rovers mainly, a mobile smelter. Would take up a medium slot and smelt 1 item at a time. Especially for mods and buttons, being able to smelt on the go would be really nice.