Dual Rangefinders priority

When using dual rangefinders for terrain following auto WP missions how does the flight controller prioritize them? i.e. is RFND1 used as the primary source of distance and RFND2 used as reference only? Can they be blended assuming they are both the same type? Thanks

I would like to know it as well. Lets say i have 2 rangefinders, one reading 5 and the other reading 10 because they are pointed in slightly different direction, is there a way to blend it and have ekf use the median?