If we consider an error of reflectivity of HR coating of PPKTP(0.02%). We could have a very different estimation of OPO round trip loss and OPO escape efficiency.
Note that here we use transmissivity of OPO of 0.2% as a prior (as entry 1538).
Note that if reflectivity of HR coating of PPKTP is 99.995%, we can explain 10% loss from OPO in loss and phase noise measurement.