Possibly. The Aux button on the TH ST16 transmitted a signal on "Channel 12". I don't have a way to tell if ST16S does the same. And I don't know what the frequency is for Channel 12.
Well there is not a bunch that can be said after that. I'm trying to incorporate a release system sense I can't seem to find how to get the one advertised on yuneec.com for the 520. Do you know any other option besides using the landing gear? Using it that way,, there are to many ways for the landing gear to engage itself.