Not pointless to wait. I think the point of waiting is making sure actual defects that should be covered will be covered, not denied based on a mod that *could* have effected something. At this point, any problems would be the OPs, either way.
Say you have a bearing problem from the factory, then your engine fails. BMW covers it. Now say you have the EXACT same car, and you tune it or put a blower on it, whatever, and your engine fails. Based on this scenario, it would have broken either way, but BMW has grounds to deny your warranty claim if your mod *may* have led to the failure. They don't have to prove it caused the failure in order to make your life miserable.
I see it from both sides, but the definitely are reason to wait.