There are two other physical problems that I had to solve and one was easily solved by the pass-through coupling modification. The first was about load timing. When the filament successfully makes its way down the long PTFE tube from the MMU unit to the extruder there are two options, from what I've seen: the successful option is when the printer pauses for half of a second and then continues to push the filament down to the hotend, and the unsuccessful option is when there is no pause, causing the filament to jam, strip, and attempt to reload again (for some reason it almost always works the second time despite nothing changing). This is heavily-dependent on the IR sensor's location, but after disassembling the entire MK3S extruder to install the pass-through coupling mod and randomly putting the IR sensor in place, I have not had this issue ever since. With the normal-length PTFE tube provided by Prusa with the default extruder setup, the unsuccessful option happened to me a lot. I'm not sure if anyone else has had this problem (I'm sure people have had problems with jams but I don't know if it's in the same way as I'm trying to describe). However, even when using the same length of tube as before, the pass-through coupling modification decreased the time it takes for the filament to get to the Bondtech gears so the printer had to take a pause because the filament reached the Bondtech gears earlier than expected. This is key in preventing the "zero wait" jams that I had had since I upgraded to the MMU2S.