I was having problems getting my filament sensor to trigger consistently on filaments that ran a little thin (1.72mm) in spots, and after recalibrating repeatedly, I noticed that my filament sensor holder was leaning slightly to the left. I printed a new one, and it also leaned slightly to the left. That's when I decided to shave the model down.
This is the Original Prusa MK3S to MMU2S extruder upgrade file ir-sensor-holder, except that the bottom has been thinly shaved off at a 1-degree angle to cause the whole thing to lean to the right at an 89 degree angle instead of 90. Then I thinly shaved off the right side by 1 degree to make the right side appear to be a straight 90 degree angle again. No other modifications were made to the model, except for Netfabb repairs.
Standard Prusa parts (PETG, 0.2mm, 20% grid infill, no supports)
The author hasn't provided the model origin yet.