Aerodynamic coefficients in SITL

Hi all,
I have a question when I try simulate my own model in SITL.
I set up the SITL environment couple of weeks ago and started to try functions with QGC and MP. It works well with default settings(I use v4.3.7, latest released one). Now, I’d like to play my Quadplane model(octa+1 prop, ~25kg) in SITL by changing parameters to learn how good it can work. I suppose all the aerodynamic coefficients and related physical parameters are in the SIM_Plane.h and SIM_Frame.h(correct me if I am wrong or any I missed). Parameters of motors/power/size are easy to estimate, but no idea with aerodynamic coefficients… Does any one know how to get a good approach/guess for all those aerodynamic coefficients? or does anyone have any good examples at the size for helping me to estimate besides of default?

Thanks in advance

Take a look at Paul’s talks on the ardupilot conference in 2022 and 2023.
they are available on youtube.