I'm surprised that no one addressed these three issues:
1: The flat area around the main dish is very annoying. Your combo might end up there and slowly make its way into the pocket. If the combo somehow manages to hit the wall and bounce back on, it would obviously come with a loss of stamina. Stamina combos could also just stall there for a couple seconds when they're up against an Attack combo to almost guarantee victory. The current tournament Stadium does not favor Stamina Beys like that.
2: There's less surface area touching the ground, so the Stadium is more prone to moving around when a heavier combo is in battle with a mobile Tip.
3: This Stadium comes in a set, not on its own, and only has one release. People are more inclined to buy multiple copies of a Stadium that comes on its own than one that comes in a set. The Epic Rivals Battle Set costs twice as much as other Hasbro Stadiums and comes with two Beys and Launchers, so buying 3 of them means you'll get 3 copies of the same Bey, which kind of makes the increased price obsolete, especially for some outclassed parts.
Overall, I don't think the rule change would benefit the Hasbro only format. In fact, it might just make it more annoying to play.
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