MMU2 Firmware 1.0.3 issue - spacer for temp. fix

there leaves no gap and the selector isn't aligned to the filament path
https://github.com/prusa3d/Prusa-Firmware/issues/1422?fbclid=IwAR1SIVRgsmSOQzIkv719cebW1efM22_tC9lI5OYdSqJQa_SeS8uU818bdks

perfect alignment is 1.0mm following the stl models. My measurement in early time of usage was 0.9mm.

this small piece will block the selector from moving too far

1st one was 850µm and was already 0.9 thick after print, 2. is 950µm