I can get a mild form of it on my M4 MBP's built-in display at "1800x1125"* but it's not nearly as noticeable as it was on the 4K external display at "2560x1440" and honestly I needed my cell phone camera zoomed in to definitively identify it, so that was more of a fishing expedition than a real problem. However, I have tried 2 different Macs, 2 different 4K monitors (both LG UltraFine also, though they differ in firmware version and color reproduction because of course they do), and 2 different interfaces (HDMI, Thunderbolt), and I can reliably replicate it under all of those combinations. I think that exact scaling factor probably has a bad interaction with the scaling algorithm. I do agree that a lot of other scalings do not produce the ringing/halo/bloom effect.

* = You have to go click "Advanced...", enable "Show resolutions as list", then when back on the main Displays page, enable "Show all resolutions", to get this and many other options -- but this is only necessary on the internal display, the external display offers "2560x1440" as a non-advanced choice