Tinker Since you have read everything about MoI heft matching I am not going to go thru all the ins and outs. I have been offering and doing MoI matching for over 10+ years. TLT 3/8" increments blend with MoI heft matching. In my experience the golfers that choose to go that way have more consistent center impacts. MoI is another way to heft match and I am not going to say one way is better than another it's another way. I have offered to change the heft match back to 1/2" increment and swing weight heft match and I have never has one single golfer ask me to change back.
The reason the industry is wrapped around swing weight, 7g increase and 1/2" is cost not because it's better or worse.
When golfers are fit with a 1/2" length graduation set and swing weight matched does the fitter start with a light swing weight and increase heft and watch effect of centered impact to find the correct heft match for the golfer and are all irons built to that specific swing weight? Or are they fit with what the manufacturer designs the set at? Why are wedges in a swing weight heft matched set always heaver in swing weight than 3i-9i. If swing weight was the correct way to heft match wouldn't the wedges be the same letter/number?