MicaForEveryone provides a option for "blur backround" which is quite close to old glass backround.
The thing is that this settings is very buggy (extremely slow resize of a windows, should click outside of window for the effect to be applied etc..) in MFE.
This feature is really great and would be a great addition to ExplorerBlurMica as it uses hooking methods and could provide better support when on the other hand MFE it does not as far as i know.

MFE Acrylic blur option:

MFE without blur option similar to ExplorerBlurMica: