The heat doesn't impact the Aileron push rods as much because they are shorter. Although it may be to a lesser degree, the heat will also impact a long steel rod. As long as you don't have metal vibrating against metal, RF interference shouldn't be a big issue. This problem mostly dates to the days of AM radios. It is less an issue with FM radios and probably not at all with the latest 2.4 ghz stuff. I have had airplanes where I used the guide tubes for the plastic rods and steel rods that had bits of they yellow nyrod material pushed over the steel rod so that it didn't flop around in the tube. It worked about as well as the plastic rods. On the whole though, I think most of us just take off, adjust our trims and live with it.