Frankly, I don't see the need for this, in particular since the MSD is cloaked and only takes five seconds to start repairing. I just often send that along with the main fleet blob, and it'll survive unless area attacks or tachyon units. When I don't have one along I often also use the damage selection filter, but not in an attempt to save every single fleetship, rather between 'engagements'.
Actually, now that AI Patrols are what they are, I often just hit one or three targets, pull back out of system with everything, then repair and return, though I do have some variations with optional unlocks.
So I don't see the need for this, but if it were to be implemented it: Rally Posts are perma-cloaked and can travel between systems at a fairly decent speed. There's 'reclaimed->rally post', damaged->rally post should be pretty flexible, and be adaptable for most of you cases such as FF, engineers, MSD.
I wouldn't mind something like this for golems (but I'd rather see them scaled), starships, and the big spire ships, but I'm not going to be a proponent of spending time on it unless it's simply implemented and relatively simply debugged etc.