Ok, I think I will withdraw my last observation. 
My previous experiments were done when I accidentally had Over-prediction reduction enabled from OpenXR Toolkit. I believe that when it is set to -8% I see the least shaky image. I understand that the setting is not intended to be used with MR.
I don’t know anymore if covering the cameras really helps. The biggest impact really is how hard you move (or your heart beats) and that’s why this is really hard to test and see what is really affecting to this.