ALternatively use the new web actions from the appstore and switch tabs with nanoflow actions, see: https://appstore.home.mendix.com/link/app/114337/Mendix/Web-Actions
How about using a wizard with separate pages where each page is a “tab”? That way your buttons can just show the next (or previous) page. You can even style the wizard steps/buttons to look just like tab headers!
There's an app for that; Tab Switcher: https://appstore.home.mendix.com/link/app/265/
It is an oldie and you will have to upgrade it from version 6, but it will be worth it.