I found a work around that will suit my immediate purpose (need a screen shot for my HOA Architectural Approval Form in order to progress).
By keeping the left and right (Gable End Wall) rails well inside the patio area the roof gets displayed in a reasonable manner, although the error dialogs are still displayed. Also the ceiling edges are well inside the roof overhang, which does not gel with the front porch which has the ceiling edge flush with the house wall with just a outer wood beam supporting the outer edge of curved Spanish tiles (probably something I can do in the Build -> Roof dialog around overhangs).
The plan is attached if anyone want's to take a look at where these error dialogs are coming from (I've left the rails visible for now as it's easier to see where things are lining up, but obviously these would go invisible and a couple of front support posts would be required (as per the initial picture above).
I'll admit while I love this software I have not used it in many years (I just checked and it was 2012 when I spent many hours with a measuring tape and evenings creating the full house plan, in order to get HOA approval for a front patio upgrade) so I'm really rusty.
Back Porch Workaround.plan.zip