I have personally never experienced the lean.
But let me comment on something. When I installed my OME lift before Christmas I measured the OME 894 spring heights and noticed that one was a 1/4" taller than the other. I doubt it was a manufacturing defect. So, I put the taller one on the driver side. I sit level from side to side. I even noticed that the stock springs were marked with factory paint to distinguish them apart.
So may I suggest swapping the struts side to side before you buy a spacer? (asuming the Bilsteins are set identical)