Probably a very silly question, but I am wondering if there is such a thing as a legendary robot mod, like the gear and weps you can find.

I ask this in part to find out if it is worth taking on the Mechanist at Survival for anything more than the thrill of it.

Mods, not that I've seen so far. Legendary robots, though, can have some nice loot. I got a Two-Shot Hunting Rifle on the first or second mission.