While the canola oil trick serves to treat the symptoms of jamming, I sought to treat the cause. The purpose of the heat break is to prevent plastic from melting too high up in the tube. If it melts too high up then it expands to fit the width of the tube under pressure and sticks. Thus, the fundamental issue is cooling. Solution: apply a generous amount of thermal paste to the heat break threads where it interfaces with the heatsink. I've gone from 50% failure rate to 0% failure rate over the past few days of printing with this trick. I've also noticed that the nozzle oozes significantly less which means no more stringy parts. Parts now come out with gorgeous surface finishes with no blemishes or skipped layers. A quick test that demonstrates the cooling improvement is to let the unit sit hot for 10 minutes, then push the filament in manually to see how high up from the nozzle the plastic start melting. Before the thermal paste, I could push the filament in about 10mm and lots of molten plastic would gush out of the nozzle. Since this trick, I can only push the filament in a couple of mm and hardly any molten plastic oozes out at all. This means less time spent cleaning the nozzle, and less stringy parts. Let me know if it works for you too!