Thank you. I saw that YouTube video explai ing generic LG Picture rotation. I want verify it will work on the one I wish to purchase.
FReepers are manytime a better info base than the manufacturer’s reps.
The key is to access the hidden Service Tech Menu that the manufacturers don’t want to admit exists.
You face a couple of issues. Kingu is correct, the thermals of mounting a consumer TV upside down can vary widely. That is one of the important reasons that commercial displays exist - to ensure that they can handle adverse conditions. And the warranty will be certainly voided if used in commercial applications.
The issue of bezel size and placement is common in digital signage. There is a reason that ultra-narrow bezels cost more - it is very hard to get the electronics from the video processor to the LCD mylar with a “zero bezel” design, while respecting the afore-mentioned thermal issues. And consumer TVs need to have somewhere to put speakers, which your video wall will not need.
You will also find that consumer TVs will often have slight delays even between identical units. One picture will be out of sync, like old Italian movies (is that profiling?)
Your best bet is to look at a digital signage box that will manage the high bandwidth video content (Thanks kingu!). You don't need to look at RGB Spectrum boxes but I would skip the new cheap Android media players. Look at an i5 or i7 media player with a powerful graphics engine.
Take a look at Rise Vision software - its free! And it may solve part of your issues that you will discover. Many other good software packages out there too.
Taking a 1K or a 4K image, splitting it into 1/4s, inverting half of the images and then displaying them in sync 60 times a second (59.94 to be more accurate) requires some fast processing. There is a reason that video scalars are expensive.
I think that you might pull it off, but the cost of your labor may exceed the cost of the hardware savings by going cheap on the TVs.