Clutch idea

Just came out here to suggest the same thing. Perhaps have it as a "Clone Hybridization Vat", where you insert two geneme sequences, along with all of the normal stuff to make a clone, and the clone that gets grown from it would have a 50/50 shot of having each trait of the "parents", with any traits that both have being guaranteed.

Or to deal with trait limits, assign any traits present on both "parents", then pick a number of traits up to the average of the number on the two parents, plus or minus 1 (for some variance), amongst the remaining pool. For example, you have a pawn with Psychopath and Ascetic, and another one with Psychopath, Jogger, Sanguine, and Super-immune. The result would be guaranteed to have Psychopath, and then would have 1-3 additional traits (parents have an average of 3, so the result should have 2-4 traits) amongst the remaining set of 4 (Jogger, Sanguine, Super-immune, Ascetic).

If you really want to have fun with it, you could also add a new building that would let brain scan templates be combined, with the result having a random backstory among the parents, and for each skill, randomly have the skill level of one of the parents and the passion level of one of the parents (selected separately from each other, and separately for each skill).

This could add a whole new level of highly ethically-questionable science to perform. I'd love to go play mad scientist with my colonists' genomes until I finally create a super-human that I can clone and replace them all with (and of course, they'll all then become my colony's power supply, yay Bioreactors!). Would also add a fascinating new dynamic to deciding which enemy pawns to capture, to attempt to breed certain specific traits into your lines of superhuman genomes.