It wouldn’t be a bad idea at all for him but logistically it’s not ideal is it? Hell developing two diffrent designs for two diffrent drivers, now thats a challenge!
All McLaren really have to do is bring both noses for Button, and run one in FP1 and the other in FP2. He should start with the nose he is comfortable with, and use it to establish a baseline for the setup. He then runs the new nose in FP2, and refines the setup. If he’s not comfortable with it, he should revert to the ol nose for the rest of the weekend. Once he gains confidence in the new nose, he can start running it more and more. It should only take a few races.