I though (take it for what you want) that you could get the HDMI out accessory for the transmitter, and use an HDMI to 3.5mm Jack (possibly wrong on size) cord to plug in to the port on the FatSharks.
It seems like that was a possibility when I looked in to it, but I didn't research fully as I began considering that I would lose the ability to use the app while flying.
I was also looking in to this for a P3A, I don't know that the HDMI adapter works with the P3S but I would think so.
I do know that FatSharks have a port for vid in and the HDMI has vid out. There are other variable but the basics seem to be there.
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