What is the ideal monitor size for text-based work and casual gaming?

Rather than polluting the ultrawide thread with more of my nonsense I thought I'd start a new thread.

Warning: This post will be quite boring and personal.

As I've been working from home for a few years now, I've steadily optimised my working environment in terms of hardware, software and lighting. I'm possibly borderline obsessive tbh.

I used to work on a 2017 27" iMac with glossy Retina screen at 5120‑by‑2880 resolution. This is still my gold-standard for text clarity, but I now use a 32" LG at 4k (3840 x 2160). Why? Because I'm now on Linux (specifically popos, an Ubuntu variant), and although I can run Linux on the iMac it won't drive the display to full resolution, and the desktop PC I run is faster.

Linux has decent scaling options now, and I tend to run 150% scaling to keep everything a comfortable size. I've experimented with no scaling (100%) and increasing font sizes in applications, but it doesn't produce as good results as scaling the whole OS.

My viewing distance is about 70cm, which coincidentally is the width of my 32" screen.

I've experimented with my LG C2 55", and that works OK at ~120cm viewing distance. So I'm pretty sure that viewing distance = horizontal screen dimension is a good rule of thumb. Any closer than that (on either the 32" or 55") and regardless of OS scaling or font sizes, I feel myself moving away so I can see the edges of the screen without excessive head/eyeball movement.

Does refresh rate matter? Not much, to me, for work purposes anyway. I can detect smoother scrolling on the TV at 120Hz vs the monitor at 60Hz, but text is still largely unreadable during scrolling. I'm not in the Matrix and have no need to read moving text. I do enjoy gaming at 120fps/hz though.

Is 32" better than 27"? Yes, slightly. For a while I switched back and forth between the 32" LG monitor and my 27" iMac, and preferred the LG even though it has a matte finish. I think because it's slightly further away I can move around in my seat without my field of view changing as much.

Would 42" be better than 32"? I don't know. It would give even more stable field of view (like 27->32"), but maybe there's a limit to that. Sometimes it's nice to lean to zoom.

How about OLED vs LED/LCD? I still reckon that OLED text clarity is slightly inferior to IPS. It's really difficult to put a finger on during use, but when I switch back from the TV to the monitor there's a sense of "ah, that's better". If I didn't have the TV for sofa gaming, I'd be sorely tempted to pick up a 42" LG C2 and use that for work and desk gaming. 

Would ultrawide be even better? There are loads of gaming ultrawides now but they're all 1440p, and I would miss the pixel density of 4k. There's an LG 40WP95C-W ultrawide 5k2k available which goes to 72Hz, that has the same PPI as my 32" 4k. Do I really need more width? I think it would take careful window management, and possibly it's more convenient to just run a cheapo second monitor for secondary apps.

So that's my conclusion: 32" 4k IPS or 42" 4k OLED, take your pick. But 27" is also fine, just a few cm closer.

IMO we have pretty much reached the limit of monitor technology for productivity purposes, but not yet gaming where people will be fretting over OLED vs LED/LCD, 16:9 vs ultrawide and 1440p vs 2160p for a while longer.

What do you reckon? Has anyone switched from 27 or 32" to 42" (4k 16:9 in both cases) and noticed an improvement or worsening for text-based work?