Broadly MeanField had a system that would map the full index of degrees of freedom to some reduced index space based on domain support. This system has been cleaned up and ported. Further, we have consolidated this system into the discretization system from where it lived in MeanField (in the operators subsystem)
The full rewrite of mean_field into something maintainable is progressing. dimensions is mostly done, discritization (domain, blocks, and fields) is done, and eos is progressing quickly
