Good info, cheers. I was wondering if they'd done something clever with the direction of the signal but compression makes more sense. Have you ever done a side-by-side comparison with an RDP connection?
Also it would have to come into a socket, via patch cable to a different socket, then installed cable up to my desk (also cat6). I imagine there's a tripping point there somewhere that could mess up the POE function, though I'm not sure if that's strictly necessary or whether you can just power locally at both ends.
None of these boxes will be truly lossless; note they state ‘visually lossless’ which is a nebulous and meaningless term.
An uncompressed 4K@60Hz 4:4:4 signal needs 12Gb/s, and the signalling rate of the HDBase-T over CAT6A interface of that AV Access box I linked to above is 10Gb/s, and it’s simultaneously sending 480Gb/s of USB2.0, audio etc down that same interface as well. The video is compressed, it is lossy, but for most purposes it’s difficult to tell.