@adler11,

Forum header is not the menu only. Forum header makes the profile page connected to forum, but when you remove it the profile page become sitewide, so it can be used for other parts of the website like shop or community. The forum header should not exist on the top of user profile page because profile page is a sitewide content, not only forum component.

it's not about the design or menu, it's about member profile usage area. In case you only use the profile page for forum, then you can enable forum header and show it wrapped in forum.