No but.......he probably would make more money doing the leveling kit. However, it's not the first time that i've heard that moving the shock to the middle ring somehow compresses the shock. Doesn't make sense to me.
Actually, that would make sense in a position-sensitive damper like the internal-bypass Fox's on the Raptor. Remember, the beauty of these shocks is that their effective valving changes throughout the stroke, so that they can be compliant early in the stroke, yielding excellent small-bump sensitivity, while firming way up later in the stroke to prevent bottoming.
Moving the snap-ring changes the height of the spring perch, but the spring's force remains the same. This extends the resting eye-to-eye length of the shock further, reducing the sag preset by SVT for the truck, and thus when the suspension is in its 'neutral' position, the piston is higher in its stroke than it was intended to be.
Sag is a critical component of suspension setup, and reducing or eliminating it can cause serious issues with suspension performance.
I'd guess that SVT's engineers spent a LOT of time tuning the suspension in the truck, and from my admittedly limited experience (my truck's on order but I've had a few test-drives) and from what I've read, they did a stellar job. Changing ride-height is one thing, but dialing-out sag is an entirely different story. I'd go with the spacers if you want to pick up the front end.
Just my opinion. . .