Setting org-catch-invisible-edits to non-nil works fine if you are pressing backspace to delete, aka you're at the end of the invisible region. But if you are at the beginning of the invisible region - just before the ellipsis - then it happily deletes the invisible text.

Also when you delete all newlines after the header, so the following text should be added to the header, it does get added to the header... but as a new invisible region. That ellipsis can't be expanded with <tab> for some reason.

Adding new characters from the start of the invisible region is correctly prevented.

I tried searching emacs' issue tracker but it either gives me unhelpful errors or just doesn't do anything so I'm trying here instead.

(emacs 27.2)

edit: found a bug report from google. not sure if it's being handled: https://lists.gnu.org/archive/html/emacs-orgmode/2019-05/msg00133.html