Try Dykstra instead of POCS.

Dykstra seems to be a quicker converging POCS algorithms. We don't use POCS per se, we use ASD-POCS, but we may be able to modify it reliably to [Dykstra](https://en.wikipedia.org/wiki/Dykstra%27s_projection_algorithm).

Search for papers on this (have not found any). Maybe this is a paper on itself, please do contact me in my private email if you want to help work on this.