I've done the "creative routing" thing on 3 planes and have never had a glitch on them. When I route the antenna, I make sure I keep it at different heights with the tubes. I don't know if that makes a difference. I know of some people with the small electrics that actually use an "antenna bobbin" to shorten it. I can't see doing that myself, but, most of those guys never get more than a hundred feet away from themselves anyway. There may be another option. The helicopter guys use an aftermarket mast type of antenna. Like the one here.
http://www.wsdeans.com/products/antenna/piece.html It could be completely hidden down in the fuselage even...