The main wiring harness is packed with wires making it hard to add new ones. Since a lot of people find they need to ground the Z turret to the various other metal parts, please include a green ground wire in the x-drag to connect the X, Z motors, etc. to the rest of the chassis.
That’s a cool idea, but if part of the idea is to also run a ground to the Dewalt I’d suggest running that ground out the opposite side of the machine, with the Dewalt power cord, away from the drag chain and stepper motor wires. You’re going to want to keep the “noise” away from the other components.
Not sure about others but my Dewalt ground is separate and heads towards the right front. On my XL the wire bundle goes to left center.