If you can spare the coin for the Flexystruder I highly recommend it… I have one and it makes printing Ninjaflex easier than printing ABS/PLA with the stock hot end. I have seriously considered using it for all my prints/filament but do not want to “waste” it 
FWIW I feel your pain on getting the tension right on those spring-loaded bolts. When I first got my Taz 3 I was ready to return it because I kept failing at getting that right but once I figured it out the rest is history. I now have a Taz 3 and a Taz 4 if that tells you how much I love my lulzbot!