A lot of people report conflicts when the 1C-Position Sensing / Compass module is plugged in with the RNS-510 retrofits but I never unplugged mine. The only functional concern I have is when the car is stopped and on a specific dash/MFA screen, the small icon compass display switches on and off with a mild flickering every few seconds. The normal (large) Navi compass screen that is shown when you do not have a destination entered with active navigation directions is fine.
Hopefully someone with the 315 will leave comments on that issue. It wouldn't hurt to unplug is and remove the 1C module from the installation list in the Gateway.