Ultimate FB, Login, Register? Using custom button/redirect?

Have a silly question.

If someone clicks Login through Facebook, and they do not have an account, it will pop a FB Permissions/Auth window for the app, and then once auth, it will dump them to Wp-Admin, with a new account.

However, if someone clicks the Register With Facebook button, it gives them option to Prefill using facebook, but doesnt make an account in one click.

I do have 1 click Registration enabled.

Is it just supposed to be that way, or do i have soemthing setup wrong?

Also – is it possible to replicate this to post and create users on multisite, but have them redirect elsewhere?

For example, I want to have a 1 click access permissions step on a Fangate page, also make an account, then dump them on a secondary page (not wpadmin).

Is that possible?