I am guessing Girard is more interested in talking to RV OEMs that would buy in Qty than dealing with DIY'rs questions.
The install would be a "B" level DIY project which exceeds the great majority of DIY'rs.
Determining where to mount (not in the way of something already in the wall that can't be rerouted), cutting the hole, not damaging the exterior panel (for reuse without custom painting the replacement), resupporting the studs, Routing the cables, installing the housing, weather tight, install a control system, ensuring nothing gets pinched or rubbed, installing the electronics, all add up to a relatively complicated install.
And if you had those skills...nothing stopping you from fabricating it all yourself
That's what I would do...
You will also hear from lots that they wouldn't put a TV outside because they have one and never use it. And from others that say the glare is too much. And others will say its obnoxious to have that being used in the great outdoors.
Also don't forget that for outdoor use, the TV itself is important. A true outdoor rated TV is $3K minimum that has high Lumens, antiglare screen coatings, conformal coated circuit boards, sealed screen bezel against moisture penetration etc. Most all companies / DIY'rs ignore this aspect...and I would too for mine...but longevity will be sacrificed.
There are also forum posts that talk about mounting a TV on an existing baggage door with swing mounts. That is more DIY friendly as a "C" level project. On the Newmar threads...
If you are asking, then it just might be that you don't have the experience to DIY this type of project. But we are here to help