I finally got around to installing these backup lights after doing all the rust proofing, nano coating, etc. first. It's hard finding time these days to do everything myself, so I try to prioritize. I was also installing a Putco Switchblade 60" light bar at the same time.
Regardless, I don't like tapping into the factory harness if I can help it, so I wanted to share what I did.
CURT 7-pin plug-and-play T-Connector (P/N: 55384):
https://www.amazon.com/gp/product/B0009FJ38Q/?tag=fordraptorforum-20
It plugs in-between the 7-pin connection under your truck (just behind the spare tire). You can tap in the BD reverse light power wire to the center pin of this t-connector before snapping in and then no need to tap into the tail light (center wire of the 7-pin section).
If you are also interested in the Putco light, then the attached 4-pin connector on the CURT harness plugs right in, then you just tap in the reverse light wire and 12V power into the 7-pin part of the CURT harness. Again, no need to tap into any of the factory wiring under the truck. However, since I have the BLISS pro trailer option, I did have to do a power connection under the dash so that it wouldn't detect anything and still provide a 12V source (their included instructions show you how to do this). Also note that you will need to use a spacer for the light to clear the black bracket and bolt near the right side of the taligaite where the light goes. I used some dense foam I had around.
Either which way, the CURT harness is great for tapping in any accessories in the rear end.
If you're looking for water resistant scotchloks, you can find them here (I still heatshrink over the top anyway:
https://www.amazon.com/gp/product/B0035R7TKO/?tag=fordraptorforum-20
If interested, here is the Putco Switchblade:
https://www.amazon.com/dp/B0198CV5E0/?tag=fordraptorforum-20