I've reworked the entire reverse Bowden system and even made it compatible with the MK2s. We are moving the spool off the frame and using a bowden tube as a feeder for the extruder. This helps eliminate not only tangles and other mechanical issues but it also improves print quality.
Your extruder experiences micro changes in tension using even the best ball bearing or likewise spool holder. The changes change the extrusion width during print which leads to uneven horizontal layers. Using a fixed length of filament in a bowden tube means that the resistance of filament stays as close to constant as possible which in turn increases your print quality. I've included an image of the layer lines you can achieve with good tuning and a proper reverse bowden setup.
You will need 2 PC4- M10 couplers and less than a meter of 4mm bowden tube which are all easily found online for purchase. I ended up using Capricorn tubes and found the couplers on amazon.
If you want a WAY better setup to hold the bowden tubes to the z axis use Christophers Z axis tops with built in holder. It's what I'm using and way better that what I came up with. https://www.thingiverse.com/thing:2825557
For the MK2s clip that attaches to the extruder you'll need some support to get a decent entry port since it hangs in the air.