They should be able to disable tank mines then, if they have room, pick up them up and use the tank mines themselves; make that rank 6 repair tool worth something!
I think the repair tool should serve to disarm all explosives. Just imagine grenade rolls in... engi throws life and limb into harms way to quickly buzz a grenade. NICE!
Im not 100% sure when it becomes a thing, but i have rank 5 repair tool and can still disarm the tank mines.
the only additional explosives to be disabled should be c4. you cant get to proxy mines to disarm them, and grenades are hard to target anyway.
I'm sorry sir if my tank mines annoy you Why don't you use the same anti-mine armor as all harassers seem to be using, they casually drive over my mines and barely have their paintjob scratched. Now THAT'S annoying.