Is TRSF the same as the California Solar Initiative “Design Factor”?

No. TSRF is an ratio of the insolation available at the site at a given tilt/az with given shading to the insolation available at the optimum tilt/az with no shading. It does not incorporate any PV considerations, only solar incident radiation. I believe that the term Design Factor used by CSI in the CSI Incentive (EPBB) is different.  It compares output (AC kWh) compared to optimum where optimum is a specific location (Orange CA). This may include PTC and other design factors that influence the DC and AC power output, such as those design factors used in PV Watts.