Thanks for finally answering this mystery for me.
I'd actually really like a TV that properly supports it because the idea of having one ethernet cable running to my TV and then everything else also getting a wired connection via the HDMI cable its already attached to pleases me, in the same way that a single USB-C cable on my desk giving my laptop access to ethernet, monitors, USB peripherals, and power pleases me.
I'd more be afraid than happy if a TV were to support that (and even more if laptops would use it to bridge a TV to the home network), simply because a TV that has internet access in any kind will download ads and nagware and upload viewership statistics in return.
Modern TVs truly have become like 1984 - there is no way a 4k 60-inch TV at 340€ is anywhere close to profitable on its own without milking the user's data for all it is worth. The actual cost of a TV is more like 900€+ if you go by the prices for "digital signage" TVs.
Okay, today I learnt.
That thing Didn't Work more than it Worked, but options were slim. Eventually it fully died about 14 months in. I didn't even bother checking to see what the warranty terms were. TS3 Plus, back in 17 or 18. What a piece of shit.
Sounds like it's a good thing I didn't bother trying again in the early 2020s and only recently bought a new dock.