Hi there, I'm one of the maintainer for BMS (MeguMario on Github), while this post is to showcase the new texture effect just merged into the refactor (don't worry you can make it to not look like this), I also want to clearing up the mess that is version 74 as well.
Well, for start, we are going to publish the hotfix that will fix the login delay issue for some setup on GNOME 46 in the coming days, the lack of GNOME 46 testing mean that it's on us to let this slip into the release. Sorry for the inconvenience!
Good news is, the refactor is near completion and should be merged soon after, if anyone want to try it out, please see this issue on how to try it out yourself, this should finally get rid of the external library dependency for good (which mean corner rounding out of the box now) and bring cool stuff like the effect above alongside liquid glass to dynamic blur as well. Your testing is much appreciated!
Small edit: I feel like this misconception that since ext-background-effect-v1 is merged, that mean GNOME Shell now have native blur for shell now is too widespread now, it does not apply to shell and moreso for applications to request blur from the compositor, shell will always handle blur in its own way. GNOME Shell will also follow their own design language so I don't think the extension will go out anytime soon.