Definitely curious about that speed article/post! Sadly my current extruder head is… heavy as hell. I printed up one of the lulz Dual mounts, and have two extruders running (one a Volcano, one a regular e3Dv6 at .6mm). Sadly, the thing is EXTREMELY heavy - and with the Volcano as the main extruder - so I just can’t move it very fast without it shaking itself apart and/or underextruding and … knobbling. Which is totally a word now. I mean the sorta wispy/blobby stuff that happens when you … underextrude.
It’s why I’m looking into that HPX2-MAX - annoyingly closed source, but it’s two extruders from a single motor, easily converted to a bowden setup if needed. I’m hoping that I can get ninjaflex working with it too. But the goal in mind is being able to move that x-carriage a lot faster than I currently can. It weighs all of 275g! I think you were the one that posted the weights on the stock extruders - I sadly don’t have a scale, but I expect the Lulz dual extruder chassis, when fully populated, weighs at least double the hexagon hotend. So… really, really heavy.