KDE provider is ready and available from version >=kde-frameworks/kwallet-5.97
See ebuild TODO.
Did you check that it works fine for you? See latest comment in the linked bug.
(In reply to Andreas Sturmlechner from comment #1)
> Did you check that it works fine for you?
My reason is install vscodium without gnome-keyring. It works.
I am using gpg-agent for ssh and git.
Kwallet used by NetworkManager to keep wifi credentials. It is normal non-GPG wallet, so i am not affected by deadlock bug.