While printing filament cooling ducts for our E3D Titan Aero toolheads, I noticed that some ducts had consistently poorer print quality on the overhangs of some corners, while others had even performance on all corner overhangs, even when printing with the same printer and filament roll.  Keith pointed out that I had switched toolheads between stock and one of our upgraded E3D Titan Aero toolheads with the surround filament cooling ducts.  I hadn’t expected the more even cooling to make that much of a difference, but it indeed does.