You are running it to spec, sat at 50mm chainline. It would be very hard for it not to be at that position. (give or take tolerances)
You can run without the 2.5mm spacer on the none drive side, but you may need to modify the sleeve (take the lips off) or run without the sleeve but this reduces it's ability to seal out stuff n dirt
. Otherwise it will be crushed.
As it's 73mm b/b then there should be no problems clamping the crank down to the splines (afaik)
Easiest way is to give it a try without the sleeve there.
BUT you then have a lopsided pedal system, even more so if you switch the spacer to the other side.
These the original SLX ring, I didn't test mine out long enough but them I'm only to 8 speed at the back.. My Middleburn I use on the SLX crank do have a grinding noise though.