Second GPS, PX4 and QGC


I have external GPS module which could provide the NMEA messages. It also gives HDT with heading (yaw) by dual antenna functionality. Beside the primary GPS ( I want to feed the NMEA messages into the CubeBlack running PX4 (or Arducopter) firmware with QGC for replacing/lowering the yaw angle weight of compass because of strong magnetic field environment in my application.

Does anyone have experience on this? Thanks in advance.