I kinda don't think anyone is trying anymore to actually match boosted H3. The problem people have with it is that it's very damped/hysteretic in low impact shots, which is IMO a positive quality that gets diminished if you try to make the sponge more elastic in the low impact shots like a lot of modern rubbers do. Boosting helps that bad aspect of H3 without greatly reducing its damping in strong shots like blocks against a fast shot, in a way that a softer and more progressive sponge wouldn't do as well.
At the same time I've noticed that it seems like if you try to increase the width of the range where elasticity is efficient by having a larger pore but softer sponge, you end up capping the maximum because the overall hardness is lower and peak elasticity is lower, because elasticity is directly correlated to young's modulus, and young's modulus is a material property and not a geometric one.
I've just accepted this but I'm sure with material science and engineering advancements some day there will eventually be something that's "like H3 but better". Although I'm unsure if it would be as durable with how soft compounds are already used.