3d printed threads and snap connectors are nice, but M3 bolts and nuts are more robust and look dope. They also make the model easier todesign print, since you don’t have to worry about tolerances as much.
STEP/STL and instructions available here: www.printables.com/model/548770-master-spool
Fuck any manufacturer who makes their own standard. We have one. We don’t need a new one. Vote with your wallet. Unless the manufacturer specifies they are compatible, don’t buy it. Simple and easy.