So I finally installed my J-Head Mk V-BV hotend (3mm filament 0.4mm nozzle) and it’s really nice so far! I’ve printed ~3kg so far and no jams or issues whatsoever.
I increased my printing speeds to 70mm/s from 50mm/s (with perimeter at top/bottom layers at 75%) and I’ve done a ~20h print without any problems.
So if you’re just printing PLA this seems like the way to go. I got mine from ooznest.co.uk