Jacob,
These are my best selling product. Of the 1000's of these bars out there, many have asked if there would be an issue on the inside rail, but nobody has ever reported that they are after trying them.
I'll tell you what I tell everyone else: If you test a few on the inside rail, and you are not happy with them, I can make thinner ones for you. If your rail is Code 83, use the code83 version for both sides.