I believe t'was only an example of what the cap was supposed to be.

But there has not been a dev or rep response that truly followed up on what the caps were.

T'was my understanding that this cap was ONLY for the Materia bonuses and not a combination of all your equipment bonuses.

I do not believe the materia stat cap was found (i.e. people double melding HP to their equipment were not capped at +280 HP and don't recall reading anyone reaching a cap yet).