This is with 85A shore hardness NinjaFlex:
Settings:
Extrusion settings: 0.2mm layer height, 0.4mm width, 1.2x extrusion multiplier (120% flow if using Cura)
Slicing: 3 perimeters (walls if using Cura), 3 solid top and bottom layers, 10% infill. Disable filling of small gaps.
Speed: 20mm/s print speed, 15mm/s for outermost perimeter, 50mm/s movements.
Temps: 230°C hotend, 45°C bed
Feeding the filament is a bit tricky, even with a printed guide between the filament sensort and the extruder, but using a lighter or torch to melt the head of the filament stiffens it a bit and makes it pretty easy to get into the bowden tube. Once it's in the tube the extruder does a good job and the filament doesn't get misaligned or bunched. With a heavy spool it might have trouble rotating the spool, moving the spool from the plastic holder onto some bearings on a filament stand solved this for me.