One thing I noticed right away is that the spacer eliminates any possibility of the wheel centering itself on the hub. That's not going to influence whether or not the spacer needs to be bolted, but it's going to make it essential that you torque the nuts at every wheel change. When the weight of the vehicle is carried on the studs instead of the center of the hub, the tightest nut carries virtually all the load until the stud stretches or breaks, then the next-tightest takes over, etc. Equal torque spreads the load out evenly and lessens the chance of a wheel coming unglued.
Jerry
