You mention "harmonics", first time I've that issue addressed with a girdle. I don't know that it could not address that issue, but suspect it's more by accident then design. All my reasoning would have me agreeing Ryan. If I was asked to design a way to connect all the cap studs together with as much flexibility as possible, with 1/4" plate, this is the design I would use. If however connecting just the two studs together on each cap with 1/4" was the goal, it probably does a decent job, if that is the crux of the problem. However back to the first point here, harmonics can be solved many ways, but only best thru a lot of controlled expensive testing when using a design as complex as a SB running across a broad rpm range. And if that is the case, the OEM's likely just fix the original problem rather then band aid it.

I say we have a classic case of:
"In psychology and cognitive science, confirmation bias (or confirmatory bias) is a tendency to search for or interpret information in a way that confirms one's preconceptions, leading to statistical errors."

Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.