@greyarea The information I've found says that the use of MynaCard chips is only for account recovery, not standard login. Also, while I'm not at all familiar as to what any of this is, I've read that MyNumber Cards use a different spec from FIDO2 based keys... JPKI + ISO 7816 APDU commands as opposed to CTAP + WebAuthn. So they don't seem cross-compatible if that's true.

>MUFJ doesn't appear to offer the option to register a passkey

This doesn't surprise me at all. Again, I'm fairly certain that the play on this is to soft-squeeze everything to "just use your iPhone with face scan to login", with MynaCard as the recovery option if you have any difficulties along the line.

If support for any hardware keys is offered anywhere, it'll be minimal and require as much hoop-jumping as possible to discourage it.