Permanent Workshop Gear Upgrades
permanent upgrades to your items. Make them HARD to obtain, something along the lines of Tech up to Tier 4, complete your mission (or, complete your campaign mission if the prior suggestion is added), and the shove something like, 500 titanium ingots and 500 platinum ingots into your say boots and then your boots then have 10% falling resistance or something
I think permanent upgrades are cool like that. I like the mechanic of doing missions to unlock stuff like that.