I recently took my first shot at printing with specialty filament -- Entwined by 3-D Fuel -- on a Lulzbot TAZ having an 0.5mm nozzle. (Note that this is the original Entwined, not the mid-2018 "v2" with smaller fibers; Just purchased from MicroCenter this weekend, and saw a 2017 production date when reading the label).
While the filament in question can be reliably and consistently extruded at full speed (as with the "Continuous Load" button), I've repeatedly had it stop extruding partway through my prints. This is much worse with lower layer heights. Even when this has happened and several MM have been "printed" with no content, pausing the print, going to the load/unload menu, and telling it to extrude filament at full speed indicates that it's not by any means fully clogged, but only failing to extrude at the configured speed.
Where should I start in tuning to try to get a reliable print with this specialty material?
I'm using Cura LE 3.6.9 for slicing. The center item of the three below was printed at 210C, with the most successful at 0.25mm layer height (Cura's default of 0.1mm had far worse results -- not included in the below photo -- with the base layer almost not being there at all; 0.175 did somewhat better).
I'm using the bed heated to 45C, in line with the manufacturer's guidance (that a heated bed is optional, but should be set to 45-60C).