That is correct. The fan I use and feets uses both can take a straight 12 volts.

The older fans and aftermarket require this controler box or the burn out pdq.

The ground is how I have my efi setup wired as well, and I setup the trinary to ground on the same wire, so it would be a simple swap for me too, as I would remove the relay and replace it with this box.

I chose to wire them up seperatly just to make sure everything worked, and it is a pain to replace my fan with the old style.

After I do some environment tests on the boxes, I may substitue my relay for a while for drivablity tests later on, but at that point it is just endurance tests for the electronics vs if it works or not.

Regardless, no way the fan will take as much abuse as I put it through in one sitting.