KeepassXC too, and I think Strongbox(?) is trying to support interop with 3rd-parties -- if anyone from Strongbox is around, you should add support for Proton Pass's format.

That's been the encouraging part in this -- 3rd-party passkey providers stepping up and saying that export/interop is important to them and that they're not going to launch without it regardless of where the standard currently is -- so again, thanks for taking that stance :)