[mort96]

Wow, why so angry?

My question was genuine. I have been trying to look into this before and not found anything on how keys are supposed to be synced across ecosystems. And your links don't explain that either; the Apple link explains how it syncs _within_ the iCloud ecosystem, not how it syncs between the different ecosystems. I didn't find your WebAuthN link before, but quickly skimming through it, I don't see anything about how keys are supposed to be synced between ecosystems. And when I have looked into this before, all I've been able to find is solutions to migrate between ecosystems, not syncing between them, which are wildly different use-cases.

If you have nothing productive to contribute, please don't.