Rebirth of a nether creature

Having the option to “rebirth” the nether into a different creature would reduce the worry of having an out of place nether creature after having dumped many hours into it.

The team synergy may have changed
The player may no longer like the appearance of the creature

May encourage experimentation with other nether builds without having to start all over from scratch on a new nether.

Or possibly the option to sacrifice/release a nether creature instead. Re-obtaining maybe half of the items used to upgrade the nether creature.

You can release nether creatures from the stable just like other creatures. If you only want to change the nethers visual, you can do so randomly via the Starvation punishment.

I would really like it if the Gift of Forgetting would let you choose which trait to forget.

Yes, considering artifact disenchanting got the same treatment it would be nice to have the same for traits.