Michael, yes, and impressive video!
It is quite possible the 58's do much better than the 48's. The dyno reports I've seen Webers vs Holley did show the Holley making more power at the top end. No doubt those were 48's, a much more common application.
All this 'number crunching' raises another question. The typical math formulas used to calculate the size requirements of a carb don't always apply, especially when it comes to race engines. I suspect the basic problem with the carb cfm math would be found in the VE area. Volumetric Efficiency, which is incorrectly ASSUMED in many cases. Using that formula one could easily conclude a single four of modest size is optimum, as far as CFM goes. I think it is clear, certainly for an FE, that 'more is better', like 2X4 or monster 58's when it comes to absolute power.
Work the CFM numbers for a 427 and I think you will find some where around 800 max cfm comes up! A number I just don't believe. From personal experience at the drag strip with three different size carbs (both carbs matching) I've found the best performance was around 1200 cfm (twin Holley 660's).