The moment they said it improves anything "1200%" should be a giant red flag. What did they measure to get that number? I don't care what it is, if it was a 1,200% improvement the product would be adopted by the major manufacturers. Think about it. If it reduced drag that much, it would improve fuel economy. Much less effective and more expensive systems have been designed for smaller benefit than that. Is EFI a 1,200% improvement vs a carburetor? No, it is not. And yet...
You're just betting that the machining on the bearing spacer is significantly better than the machining of your hubs and the location of the bearing races. For a 1200% improvement those hubs would have to be really poorly machined.
I mean seriously, they started talking about drag from the wheel bearing seals. First, that has to be a tiny fraction of a percent of rolling resistance. Second, if you loosen up the wheel bearing seals, guess what you're gonna get? Greasy. Might all of this make some tiny improvement in rolling resistance? Maybe. Doubtful, but maybe. But even if that means you can push the car easier, just remember, you're not even 1 hp.
A 10% improvement would be massive. 1200% is bullshit.