When the "This consumer is for use only by..." checkbox is checked, a bunch of form fields get hidden as irrelevant for owner-only consumers, but the confidential checkbox doesn't. But it isn't really conceptually meaningful (what does it mean for a client tied to a single user to be public? it's usually defined as being able to keep the client secret secret; but while owner-only clients do receive a client secret, they are banned from all the endpoints where they could actually make use aof it), and it has no practical application (the only impact of the checkbox is forcing PKCE when using the authorization code flow, but owner-only clients cannot use the authorization code flow).