You can use Startup and Shutdown options to hold you sim in position when using motors that can be back driven when not powered: https://www.xsimulator.net/communit...ation-for-oculus-rift.7684/page-3#post-111568
With JRKs 221 is the on command for Position, 63 tells it where to go and 225 turns it off: https://www.xsimulator.net/communit...ght-with-oculus-rift.6179/page-14#post-106293