Something I just came up with.
I kept losing a planet I didnt intend to actually keep but it is needed to make the jump to the next planet so I wish to keep it, even if just to keep the adjacent planets in supply.
So I put a cloaker starship nextdoor, hiding a transport with in it a colony ship. When the CC got nuked I just send in the transport, build a new CC, build a new colony ship, hid it in the transport and send the transport back to the planet where the cloaker is waiting to hide it for the AI
Put a couple of mk1 engies in the transport to speed up the procedure a bit.
I came to this as I was hiding my Zenith Space Time Manipulators at the edge of planets under a cloaker, and they stay alive even if a planets defences fail