I attempted to do 1 pokemon at a time, it seems that yes to many pokemon that aren't normally registered to the game crashes it, except i've run into another problem where ive transffered 3 pokemon over to bank and home and attempted to transfer a rillaboom over and its crashing again but anyhow, thanks for the reply!
What do you think would be the best method of hacking for the sword and shield pokemons?