I am new to the px4/gazebo, and tried a lot of internet searching but couldn’t get a proper answer. I am trying to modify the IRIS model physical parameters e.g, changing the thrust of iris motors, changing the size of the propeller, according to my drone parameters, etc, for that, I need to change physically as well as control parameters to have a balanced flight. Can you please help me to clarify which parameters do I need to change, sdf file for iris is of 700 lines and how can I understand the whole file. Is there any description/explanation for the file so that I can have a proper understanding? Also, after modification in physical parameters, which areas in px4 do I need to change so that I can have a proper flight without and imbalances? any suggestion, guidance will be much appreciated.