if I add the register and login shortcode, I get a h2 with the name 'register' and 'login'.
Is there a way to remove or change this title?
It has to be possible because on the MB User Profile page is a (even dynamical?) custom headline for the registration form.
Yes there is. This is defined in the file mb-user-profile > src > DefaultFields.php at line 25: 'title' => 'register',
Why this is hardcoded is beyond me.
It seems like every post I make ends the same way. Here to, this is true:
I am more than happy to contribute a pull request to either a) Allow the title to be translated: 'title' => __( 'Register', 'mb-user-profile' ),
or allow the title to be filtered / set to blank within the shortcode attributes.