Nah. I didn't mention the model of router. But note. It had a processor that was unsupported on the aforementioned third party firmwares. You kinda' answered your own statement as it did not contain a BCM chipset. Or Marvell.
If it was Marvell it could have been one not yet having source code. It didn't really matter.
On my trip at the bar in question past Teddy to grab his pen and round table to grab the stapler. The issue was identified. A solution was found. Short of purchasing a new unit. And smiles abounded.
No biggie really. Nothing to do at all with site connectivity here as in post #1.
Looking at an R7000 with its flashy led's a few feet away. It had Vortex. It wouldn't do an AiMesh with an RT-68. And WDS not one bit at all. With dd-wrt from using client bridge (which always worked well) WDS setup and ran perfectly.
Not bad huh? I mean. For not attending haaavaaad. Probably because I love to drive and paaakin' da' caaaa woulda' been a pain. Pfsense, pfnonsense, jtag, serial, bla bla. Done it, do it.
Oh. Even after a factory reset on the bar router. A firmware back step wasn't possible. Yeahhh.
Sometimes. Believe it or not. Dipping your toes in the lake, sitting on the dock. With a cane pole and a can of worms is pretty relaxing. Try it sometimes. With a can of beer even. And just be stupid for a bit. But smarter than the fish hopefully. You may meet your match!