Gravity feed spool holder with roller bearing so filament move with virtual no force required. If you extruder drive is not just spring loaded, adjust the tension with a test print running. Loosen it, and then very slowly tighten it until the filament starts moving.. then a air more. Thats it..
No retraction
The above is for Ninjaflex, Cheetah is much stiffer and not as much a problem.
Good luck it takes a lot of fiddling but can be done.