An x1 slot is an x1 slot, the PCIe version will downgrade but there will still only be one lane because that’s all the slot physically has connections for. It will effectively be a PCIe 3.0 x1 slot.

Pretty sure if you put a PCIe 3.0 card in a 4.0 slot the slot will drop to 3.0, and 1 PCIe 3.0 lane probably isn’t going to work great with a card meant for 4 of them.

Not having a dedicated app on the LG TV is not an option.

When was the last time you checked? Jellyfin has had an app on LG’s webOS store for a couple of years now, although older TVs didn’t get it until a few months later. I’d given up on it and bought a lifetime Emby Premiere licence by the time by TV was finally supported.

Nah, Idiocracy somehow got to 2505 with a livable Earth. We are not on that track.