I tested leaving part of my 200+ day colony behind to slim down while I pursue the mech hive. This is from deleting my anchor and glassing the tile. I imagine abandoning the colony will have a similar effect.
It looks like dev mode destroying a colonist has no immediate effect. Should I just do that? Maybe I will abandon 1 or 2 to have at least some mood hit

Or maybe id like to leave it abandoned and watch it all burn....

It does not