The treatment of Group elements and their layout functionality in Edit Entry mode is absent, so plenty of opportunities for improvements if you ever run out of fun things to do <grin>.
Just to let you know I have come up with a solution to make Group Visibility work on admin v’s front-end mode.
Hidden field with default value = ‘Public’
On form submit change state flag to ‘Admin’ (or empty if preferred)
Conditional logic on group element to show/hide according to this field value.
Yes it unfortunately means a ‘variable’ field is on show in admin but I can live with it.