Great thoughts! I was trying to figure out how to work the dyad angle in, and your idea makes sense.

That’s also a good idea about the Threepio line. I’ll admit I don’t have this movie nearly as memorized as the others.

I wonder if singling out the throne as an object of death-defeating power is too obvious here. Perhaps the line doesn’t need to be changed too terribly much:

“Exegol does not appear on any star chart, but legend describes it as the Eternal Throne of the Sith.”

Or perhaps “…legend describes it as the Throne of the Sith Eternal”, since that is actually the name of their sect.

This hopefully gets across that the power of the place is in the throne while not spelling it out completely. It also gives some idea of what the power does, namely, defeat death.