Designed to work in coordination with S1 Pro Reduced Height Spool Holder
https://www.thingiverse.com/thing:6053261/files

NOTE!!!

It WILL lessen your available print height so be aware of that. Also, you'll need to remove the channel "cap" that houses the filament sensor wire. It needs to be long enough to reach the other side of the sensor now. I did extend it down and back for clearing the belt, however verify your upper belt won't rub through the sensor wire.

The TPU filament looks tight in the picture, however there is ZERO tension and filament flows right through.