I had originally started down the road of connectorizing, tried several different styles, then gave up. Motors don't go bad so often that connectorizing is worth the effort. I left the motor tails long and just went with butt splices. Lightly twist the black/green wires together and the red/blue wires together to help reduce EMI.
In an effort to eliminate my EMI induced false endstop triggers, I've also dumped my 18ga parallel conductors in favor of 22ga shielded twisted pair for both the motors and endstops. Black/green motor wires on one pair and red/blue on another.
Oh yeah...also a lot less bulky at the Duet2 since I've got 8 motors. 🙂