I was reading this viewing it the same way as ForeignRS, wondering why turning the engine over would matter, lol
Just take them out and keep them in order.
Im really not convinced by the arguments against using a very weak magnet on them though TBH, ive done it so many times in the past with other engines and not had a problem, but a valve grinding stick tends to be my weapon of choice just in case there is some truth in the paranoia.