I'm running the RC reinforcement and it's already seeing some surface rust in less than a year. The bolts are also rusting and I've planned to coat the bolts and plate in Van Sickle matte black farm implement paint. I don't live in the rust belt and we've only had one week of snowy weather with salt added to the streets. We also keep the Bronco extremely clean so this is kind of a bummer.
Sorry you're having rust issue with your RC tailgate reinforcement, and agree, your solution should work.
As mentioned, there are several rust examples on the internet. I see, several specific b6g mentions on RC tailgate plates for Jeeps from years ago. Here's a more recent b6g pic from '22 on a Bronco RC plate:
I'll admit that if mine came with this, I may have missed this sorta blemish. Without removing the spare tire, I just rechecked our tailgate and see no visible rust, bolts look clear, it's firmly attached and doesn't rattle.
We live in a very snowy foothill Colorado location with lots of road salt applied as de-iciing treatments. Here're pics of road salt this morning near our driveway:
Obviously, our snow plow guy got carried away with his spreader here, but you get the idea - Yeah, we have road salts here.
Our '23 Bronco does have some rust. LOL here's it's rear drive shaft - Seems to be Ford's idea for cathodic protection..
Cheers