NikoL, SudarshanK, RickS
We've analyzed the measurements made to date with our updated Pcal laser power calibration standards (see LIGO-T1800359-v2 and LIGO-G1900393-v4).
The method used to arrive at the O3 starting values is described in LIGO-T1900134-v2.
The WS/GS responsivitiy ratios ("Final values" in table) at in the attached table.