Personally, I've been happy using an LG TV for a single monitor setup. I have had to switch to KDE Plasma v6 for better font rendering given its unusual OLED pixel layout, as well as for native HDR support. But it's been nice to have a large physical font while still at default DPI. Although, I wouldn't't mind upgrading to 8K later when they get affordable, as the smallest 4K TVs at 42" happen to push the physical DPI down towards that of just 1440p panel.
Have you had any luck with projectors for coding? I've only ever used them for large mob-programming sessions, like during hackathons. I feel like the low/narrow contrast of projectors makes it hard to use for dark mode, not to mention the space real estate requirements. :P
The real estate requirements are real and if you don't have the space it simply won't work - but they are absolutely fine for text legibility. An important thing to remember is that, because you're viewing the reflection of the image instead of having a backlit screen, (outside of matte e-ink options) I've found it a lot less fatiguing on my vision than a traditional monitor. So, while I still prefer dark mode out of habit, even bright sections of the image for extended periods of time doesn't make my eyes sore in the same way. Lastly, as someone who wanders and dances while they work - it's much easier to keep focus on the screen as I migrate.
I'm sure it's not for everyone but it's an extremely comfortable way for me to code.