SITL init script vs SYS_AUTOSTART init script

Hi! I have a question about SITL. It uses init scripts located in “posix-configs/SITL/init/ekf2/filename”. This script points to other init script via “param set SYS_AUTOSTART XXXX” (pointing to file located at ROMFS/px4fmu_common/init.d/XXXX_name). The former and the later has similiar commands (for example sets control parameters with set command).

The question which has precedence? For example both files





“param set MC_ROLL_P 6.5”

Why 2 similiar scripts should be used? If they serve different purpose during simulation then what is the difference?