Unfortunately, Bane's not exactly friendly towards your other face-down morph creatures
Giving that knowledge to opponents is often good since it can delay them doing what they otherwise might have, offering us a time window into other action
Exile the top card of your library
You avoid them by describing the condition honestly using standard grades, photographing both sides, and showing any flaws up close
Now, you may have up to 15 cards in a sideboard, and can add or remove cards as you see fit, so long as your decklist remains legal
Or you might end up like the Pokmon dad who held on to every card because his kid loved themwhich, come to think of it, is a pretty great outcome regardless of the market price