Yeah I guess.Here is my take on it. If these birds survive, then they prove that they are at least able to pass on their genetic resistance to Mareks. That would then allow you to help create a closed flock that is resistant to whatever strain you might have.
But what about if I want to show?

One thing I was thinking of doing is buying hatching eggs next year early enough to have pullets and cockerels for show, show them, sell what I don't want and breed the best I have and work on breeding resistance.
I don't have a separate property to raise show chicks so my options are limited.