Are you referring to the kit user guide and an relevant application note:
There is good documentation on the Cypress site that explains how FOC works. As for documentation about PID control on that particular setup I don't think you will find anything. I started down the route of reverse engineering the Cypress code from assembly to model in MATLAB and try and apply a PID, I got as far as simulating the PID control after the ramp up of the RPM. All good fun, but I don't think there is anything out there that tells you what to do...