Hi @gecko welcome to the forum and the app.
Yes there still remains various widely used omissions from the industry not found in the Visual CSS Editor. But perhaps since you have made this post CSS Filters will now be addressed also. That’s what happened when it was pointed out that Gradients were missing in this thread. They were then added using that suggested Grapick library.
CSS Filters should not need a library (but they also exist if needed) as they should be much easier to implement. Both Box & Text Shadow are present already and have blur so CSS Filters in general should be able to be implemented as well. Plus CSS Filters have good support of course SVG filters could be used as fallback if truly desired.
An example might be CoffeeCup’s Site Designer (below), but various other apps support them as well.
Good luck with your request, but yes it seems overdue. 