Take a look at 3 panels and transformers. If you make the transformers single phase 480-120/240, there is no harmonic problems on the neutral.
That being said, I don't think you have a problem with your proposed installation. I have seen very few documented reports of problems caused by harmonics on three phase systems. Almost everything that I have ever read about this "problem" has been published by those with an economic interest in solving the problem.
Don
