[Suicide Junkie]

Problem: what if you put two repair bays on a ship?

With repair bays as top priority, the first will repair the ship, then the second will repair the first + more of the ship.
Next round, the first repairs the second + more ship

And so on. You would just halve your repair rate.

Only If both bays were undamaged and couldn't repair the entire ship in one turn, then they might both be used & destroyed at the same time.