I don't think it should be a huge deal, that's where my other tapped hole is I believe. The hole would be close to the balance tube anyway, so I don't think the effect will be detrimental to performance, and likely to the contrary, be beneficial. It's what I'm planning to do with my triples, so hopefully it works fine that way.
You can use a Coke can as a catch can if you want to. No big deal there.