This is ridiculous, it does not disable the tab, only hides it.
Changing field behavior doesn’t seem to work on the front end with acf_form even though it works on the admin areas. I have tried many filters and actions specific to acf, tinymce, wp_editor_settings, nothing works. Trying to unset toolbars doesn’t work even with the example code in the documentation. The only thing i could do is disabling visual editor, even then the quick tags won’t disappear.