There no reason why you should leave it like that- space everything till its clear and thats all
Why would you want the pipes rubbing the frame and possibly causing a problem- metal on metal rubbing and vibrating on eachother is gonna lead to a issue
Your going to dent and ruin your pipes!
Just make up some small spacers or just use some washers!
But I'm thinking, and my buddy runs these pipes and they seem to fit a lot better, he doesn't have any rubbing issues!