Hi 1P_Dave
I've never ignored the passkey support for this as never seen it appear in 1p.
I just checked my login credentials and I don't have the main playstation address, I have something called my.account.sony, which is the correct address for when entering login details.
Should I switch the to the main "playstation.com", watchtower will likely pick the passkey support up then.
Update/
If I add playstation.com website to 1p credentials watchtower lists passkey support.
I still need to keep "my.account" web address in the list though, otherwise autofill doesn't work on the login page.