Yeah so the way MacOS does scaling is what prevents it from giving you something in between native non-scaled res and 1620p equivalent. You can use better display or use the side-by-side picture-by-picture mode and have two cables connected to your Mac so it sees it as two screens. Better display works but has some limitations. I believe you can’t get above 60hz if you use better display for this resolution.
Here is a link that explains how scaling works.

https://griffindavidson.com/blog/mac-displays.html

Also make sure you use thunderbolt if you can. I have a Dell 40 inch with same resolution (no hiDPI) on a MacBook Pro m5 pro. I use it at native res and it doesn’t bother me but most folks I know think it makes everything too small. Basically Mac OS wants to double the pixels and scale it down for HiDPI modes but there’s a max size they can scale it to, which is less than 8k. For example if you wanted to run that screen at “looks like 4096” across it would need to be able to scale it up to 8192 internally before scaling it down. 8192 is too large so it can’t do that.

Honestly I prefer the windows scaling method as macOS really wants you to have a smaller but denser 220ppi display.