My experience is that it makes a lot of things visibly blurry. Has that improved at all?

I use 150% on my main monitor and everything looks perfect except for two proprietary apps installed through flatpak: Zoom and Spotify. These two are not really known to be quality software in the first place so I think it is safe to blame them for this quirk.

Indeed; it works perfectly on my postmarketOS PinePhone, which has the most recent stable GNOME release.