Can Magical Lineage reduce a spell’s level multiple times?

Oh wise brains of the internet, I implore thee

Magical Lineage states "Pick one spell when you choose this trait. When you apply metamagic feats to this spell that add at least 1 level to the spell, treat its actual level as 1 lower for determining the spell’s final adjusted level."

If applying multiple metamagic feats to a spell, such as Maximized + Empowered, would Magical Lineage reduce the total adjusted level by 2 (once for each application of a metamagic feat) or only once regardless of the number of metamagic feats?

My initial take is that it only applies once, regardless of the number of metamagic feats applied, but might as well double check and make sure it’s right.

I just want to know whether I should be preparing Maximized Empowered Battering Blast into a 7th level slot or a 6th level slot.

Thank you.