Well, just for clarity, based on my phone conversation with Bishop Williamson on the subject, he appears not to have studied the matter.

So while his conclusion (ie., the technical possibility of sedevacantism) would logically suggest he had rejected the claims of universally accepted pope’s being dogmatic facts, it appears he reached the conclusion of the technical possibility of sedevacantism in reliance upon Archbishop Lefebvre’s occasional words that such was a possibility, and not because he thought the UA argument didn’t apply.

What would BW conclude if he refreshed his studies on the matter?

He would finally come to the conclusion that the MAGISTERIUM is the "yardstick of infallibility" and not Tradition (nor Scripture), and see that it's not possible for a public heretic to be the Pope (as IS the Truth and as WAS said by Archbishop Lefebvre shortly before Assisi) and conclude correctly that a Pachamama honoring, pedophile protecting, heresy spewing freemason who refuses to call himself the Vicar of Christ is not Peter no matter how many of the ignorant believe him to be.

Thanks for bumping this thread.

I was just thinking about this, almost exactly 4 years ago. I stayed with a Trad Catholic resistance supporter, who nudged me into Ham Radio!
I was neck deep into studying electronics at the time, and he suggested I might enjoy ham radio. He was right of course. The rest is history.