Using a local build from 9/11/2019, I am testing the NPlate SRP model. See the attached script, NPlate_Propagation_SRP_Model_Compare_Sun_Orbit.
The script, NPlate_Propagation_SRP_Model_Compare_Sun_Orbit, uses two fictitious s/c, each with a dry mass of 1000 kg., in orbit about the Sun The SimFermi s/c uses a canon-ball SRP model with Cr=2 and SRP area of 500 m^2.
The Fermi s/c uses the new NPlate SRP model using two plates. The attitude of the s/c is such that the s/c body X axis always points towards the Sun. Plate BP! has full Sun and Plate BP2 has no Sun. The area of Plate BP1 is set to 500 m^2 and the plate is modeled as having a Specular reflection coefficient of 1.0.
After one day of propagation, I expect the two s/c two have the identical position so that variable Pos_Error is close to 0 but this does not occur.