Taking into account that all metamagics are applied to the base effect and don't feed from one another.
To my knowledge, this is incorrect, and there is no such rule covering it (excepting Empower Spell and Maximize Spell, which specifically call out how they interact with each other).
Metamagic feats "feed off each other" just fine in most cases. For example, an intensified maximized fireball at CL 15 would indisputably deal 90 damage.
I remember during the 3rd edition era either reading something in some obscure book or something on the WotC site saying that Empowered Maximized stuff empowered the roll and then added to the maximum. So, a 10 CL Empowered Maximized Fireball, at least back then to my recollection, would deal .5(10d6) + 60, not 90.
But yeah, there's nothing in Pathfinder about that.