So it does, yes. I forgot about that, since I needed to write my own wrapper to paste both username and password (stored on separate lines) anyway. Thank you for the correction, I'll update my post.
Of course one has to set it up, it's not an integrated solution. But GPG provides interesting features like storing encryption keys on hardware devices. Some devices like Yubikeys can have touch-to-use enabled. So each use of a secret requires a touch (after PIN but that's once a session). Perfect combination of convenience and security for me.
Do you mean this:
> YubiKey challenge-response support for strengthening your database encryption key
From https://keepassxc.org/blog/2017-06-26-2.2.0-released/
Then it's not clear for me how this works exactly.