re: The Golden Bear and Miura are collaborating.

I've never run the numbers but from my experiences here is my "hot take":

examples of blade yardages:
4 iron. good strike goes 190 yds, off center hit that isn't awful goes 180. Garbage is garbage on any club.

7 iron. good strike goes 165 while an off-center hit goes 155-160.

Example of GI irons:

4 iron. good strike goes 190 to 200 while an off center hit that isn't awful goes about 175. Again, garbage is garbage and I'm not really talking about that.

7 iron. good strike goes 165-175 while an off center hit goes 155.

I am just plugging in numbers as an example. I have always found that GI irons have a super hot spot on the club face somewhere that is even wonkier than a good strike. I remember playing a round with a buddy in high school and he had the new nickel plated Ping ISI irons and hitting balls from 170, we had some fly 190 and some would go 150. They were wildly inconsistent distance wise.

Now, I know you are referring more to the players/forged cavity backs like a 620CB and not a t300 iron but I have found off center hits to be more inconsistent on cavities than blades over the years.