I just ran into this because I was only getting about 10fps with three additions to export.lua: SimAppPro/WinWing, MotionSysems, and SimShaker. I thought it was a MotionSystems problem, but when I played with it more, I found out that it is the order of the lines in export.lua that mattered. If SimAppPro is listed first, I was getting 10fps. If it is listed last, I get 90-100fps. If I turn SimAppPro completely off, I get 125-135fps (this is all at 4K with a 3090). This is SimAppPro 1.7.23_Beta.