repair drone is good, what makes me sad is that repair drone build considered "cancerous" just because it allows to stall. But stall build isn't bad; what's bad is players can only encounter stall builds at high levels and only with diamond shell+repair drone+shield combo, often with push-away weaponry.
so yes, need to introduce repair drones at least at Legendary level, and maybe on Epic too. And definitely also add campaing opponents with pre-defined stall builds, along with hints on how to beat it. This will move repair drone stall from "omg wtf imba nerf" to "oh I remember that build from campaing, its strong but I beat it and so I can beat you as well"
And whats also would help is introducing other ways to stall: maybe its 100% shields with specific, strong limitations which allow to break it if you are not dumb and then proceed to smash the hull; maybe its some torso with ability to completely refresh its health from any level but with low base HP and bad resists, so if it fails to "phoenix" in time it will break easily; add your ideas as well.
Of course God Mode users will cry - ignore that