Hi Colin. I also got a new to me Pilot, last week. I have an HDMI to RCA adapter, (Panasonic GH5) which I got on Amazon for $13-ish. I separated the red and white wires, cut them off since I won't need audio in the 5.8" monitor.It needs power, but you can always either get a V mount or gold mount battery with a USB port and run a wire up the post, or have an external USB battery and figure out a mounting option to power the adapter. That method will actually help you add weight up top, if you need to.
I have taken the Silver class with Rey Reyes. If you haven't done any training classes, I highly recommend them. They are worth every penny.
https://www.amazon.com/dp/B07GRXDZCF?psc=1&ref=ppx_yo2ov_dt_b_product_details