I had an issue with MMU unloads completely ‘bypassing’ my filament buffer, going all the way back to the spool and unwinding.

Made this little clip to apply just a bit of resistance to the filament on the ‘spool’ side of the buffer, to encourage the filament to rewind into the buffer instead of continuing on past it.

A couple disclaimers:

• The fusion model is horrible, it's an end result of lots of changes, deletions, etc…for such a simple part, it's a mess.
• Made out of ASA, not sure if PLA would break
• It is nearly impossible to install. Very, very tight fit. Apologies in advance to your fingers.