Support for PDE Whose Spatial Derivative Order Exceeds 2

I've been stopped in v9 for a long time and don't consider myself as somebody actively using the FEM framework, but since nobody has mentioned this for so long, I'd like to add. According to the FEM-related question coming out here, this seems to be the most needed missing functionality. Just search femcmsd in this site, you'll see… only 9 related posts? Well, perhaps the keyword is not always included…