It’s really weird though, to think of a dagger pointing like a compass towards only one of two wayfinders, and the furthest one away at that. I assume there are two wayfinders as a callback to the rule of two, as if both master and apprentice would have one of them in days of old? I don’t know. So what if Kylo gained the Apprentice’s wayfinder at the beginning of the film, but the Master’s wayfinder was still to be found? That way the dagger’s purpose would make sense as a way for Sith cultists to travel back to their master wherever he would be at the time:

“Only two grant the way to Exegol; Novitiate and Master. Attune with the spirit of the Sith and passage to the Master only this blade tells. Only this blade tells.”

Or better yet:

“Only two grant the way to Exegol; Novitiate and Master. Anoint thy spirit in darkness and passage to the Master of the Sith this blade tells. This blade tells.”

I like the idea that there may have been many blades at one point used by many cultists, so removing the ‘only’ from ‘only this blade tells’ will allow for this interpretation.

Also, just a random thought, but have people considered how it would play for Rey’s pals to know that she basically has to become evil to find Exegol?