Hi swuphoto1,
I am not from Laminar Research; just a flight simmer from down under.
Obviously you have seen the videos from Russ Barlow from which I will not make reference to as a possible solution avenue.
On the other hand have a look at the following link from Michael Brown found at https://www.youtube.com/user/col2mab/videos You will need to take some time in scrolling through his list of videos which deal with multiple monitors.
Michael operates a business in the USA called XForcePC which specialises in building PCs for flight simulation. He specialises in units for X-Plane. Laminar Research has a preference for this business as the only supplier of PCs suitable for X-Plane.
Now,if this link is of no help then lodge a bug report as suggested in the link provided in your originating question. There is no link between Laminar Research (X-Plane.com) and X-PLane.Org The bug report can be found at http://dev.x-plane.com/support/bugreport.html
As a side issue I understand that FreeSync or GSync has no bearing or influence on X-Plane now that multiple monitors can be used/configured for X-Plane when using multiple instances on a PC with a single legal copy of X-Plane.
Good luck.
Glenn