Can you actually connect HDMI input to a thunderbolt only display? I have the LG 5K thunderbolt-only display and cannot use it with a desktop PC due to this issue.

You'd still use a 5k display in a non-native 4k resolution (surely the xbox doesn't support higher resolutions?), which might be ok for video and most games, but it's not a good solution. I'd just get a half decent, affrodable 27" / 4k display for gaming and keep the Studio display for actual work.

Plus, you can use the additional 4k display as an extended macOS display when not gaming. I mean there's never enough screen real estate.

Would something like this work? Xbox or gaming console to Apple Studio Display. https://www.amazon.com/Anker-DisplayPort-PowerExpand-Aluminu...