What good is a little bit of centre weight going to do when you have these two brute-chonky steel rims?
It’s a matter of degrees - actual max rim weight leaves a fragile aluminum frame for the steel rings. when you slide it back towards less rim weight you have a bunch of choices to make as you add more back into the aluminum. My designs so far have had big rings ranging from 13g (Exia) to around 20g (Converge). Both very large rings, but the difference between them is also big. And I could imagine a yoyo with a 14g, or 16g ring that plays to different characteristics.
If a design has the desired mass moment of inertia (the rotational one) but has less mass than desired, then you add center weight or low mid weight. This slows down the motion during boings, for example.
Another option is to actually decrease ring mass and put the mass savings back evenly into the aluminum, which makes it sturdier (but also changes the rim/center distribution). Or, use that mass to make the axle longer, or use a flat cup, or some other feature that requires more aluminum to realize.
I just look at designs like the Peregrine and Hummingbird, and don’t understand why they mention that have have added centre weight. Isn’t the whole point of huge steel rims to concentrate weight in the rims? Doesn’t this also counter any center weight? Isn’t that the point of huge steel rims?