Altering your suspension will void your warranty (technically) for suspension components. But I really don't see how this modification could possibly cause any damage to the rest of your suspension--So, keep your stock bumpstops and switch them back if you ever need warranty service on your X.

Note: I would not recommend this if the part in question were, say, a turbocharger. Or any other part that would INCREASE wear on your X. I am not in favor of leaning on warrantys to get a free lunch.