it works but even then, “no sorry, I decided I need the big red ball” feels more natural to me.

Or if a "Big Ball" is a thing, like a brand name lol.

Exactly. My personal hunch is that the supposed "required ordering" of adjectives isn't real, and the real "rule" is related to the tightness by which the adjectives are bound to the noun -- least separable go last. It's just that, in practice the semantic tightness corresponds to that rule.

In the extreme case (like you gave) where "BigBall(tm)" is an irreducible thing it itself, then of course "big" goes last.