This uses one rubber wheel bearing from an old vslot Ender 3 and a few strips of PTFE tubing to make a horizontal spool holder. This is pretty low friction; I suggest using it with another length of PTFE tubing to the hotend intake.
I included a wire exit hole in case someone wants to pop in a magnetic reed switch as a watchdog to ensure that the spool is still moving as the print goes on; if the spool stops moving, you have a jam or a runout situation. Seems like the most sensible place to detect that vs inline gadgets. I'll leave it to some smart person to implement this and hopefully remix and provide code.
I included the freecad file for this so you can customize it for whatever bearing you happen to have in your junkbox and so on.
The author marked this model as their own original creation.