Random thought....
Friend of mine uses a milliing deck most of the time. 0 damage potential (literally, not even a 1dmg somewhere) and heavy on discards.
Hera stats "After the action phase ends, if that vehicle is still in play return it to your hand" -> would this trigger before the losing condition that sees you have 0 cards in hand or in deck?
if it does, this would effectively make you immune to being milled to death as long as you could get it out of your hand faster than he can discard it.