If you decide to continue with the endeavor, Onkel Neal might want to use your "Bonus Narwal RFB/RSRDC Config" mod...
lol - Don't forget now, you can edit the Save folder for your crew slots, but any conn 'Updates' will wipe them out, as you previously experienced. You also want to update the "base" upc files in the Submarine and UPCData \UPCUnitsData \UnitParts#SubName upc files ~AFTER~ proof-of-concept is complete. Nothin' to it 'cept to do it (and then go crazy and cross-eyed)...
