It's an old proposal: The order in the Frontend Form should be better or more logical:
at the start in the first Tab: WHERE WHAT WHEN FORWHOOM, then the rest (details for these W -words
in the second Tab: the things more special for experts (custom fields and metatags)
in the third Tab: the attachments.
Testing JEM 2.3.0 beta3 local on clean latest Joomla (3.9.11) Protostar php7.3.8 (no mails)