I have no experiences with mapping at all.
H520 is not and will never be remote ID capable.
I must say I don't have a H520. The only thing I have is a H520 motherboard bricked with another PX4 FW. It's OK to do some experiments but I would like to have an original H520 test system, no need to fly with, only for reproduction of H520 FW behaviour.
br HE