Your understanding is correct. I find it interesting that Rico is branded as suitable for students, whereas Royals are branded as suitable for students and professionals. The Royal page on D’Addario’s site has a big picture of Bob Reynolds, who has used them for years.
I do have a vague memory of D’Addario saying something about updating their machines a few years ago. It may coincide with the introduction of the USDA organic certification on Jazz Select reeds. They have now moved all their reeds to this status. It is these new ones that seem to play like the Ricos of yesteryear.
Rather than compare dimensions, I have held the new ones up to the light to see the shape of the heart. In general these seem to have a better shape than Ricos I got in the early 2000’s. Heart goes farther up toward the tip, and is darker. I was talking to a fellow saxophonist about this Monday night, and held one of my 6 current reeds up to the light, and his reaction was “Oh wow! Strong heart.”
Time will tell if this continues….