I'm sorry to hear this about the LG browser's video mode, but not surprised. How did you determine it?
By testing and logging ;-).
The browser itself is just a 'full-hd' application, it doesn't utilize the 4k resolution of the TV. You can see that also by normal browsing when looking at the pixel raster. I assume this is done for performance reasons, webpage rendering in 4k would make the TV browser even slower ;-).
This is at least the case a 2015 and a 2016 LG TV model that I've tested, maybe newer ones or TV browsers from other manufacturers are better here...
That browser also crashes on panos with large cubeface sizes, so is really not much use.
With multires any sizes should be possible.
But by using the TV as a 4k 3D monitor, we should still be able to show interlaced stereo from web pages.
Yes.