Stacking Extend Spell

[Matamane]

Is it possible? For example, would raising it by 2 levels be tripling its duration?

[SparkMandriller]

Multiple Metamagic Feats on a Spell

A spellcaster can apply multiple metamagic feats to a single spell. Changes to its level are cumulative. You can’t apply the same metamagic feat more than once to a single spell.

Sorry bro.

[Yuki Akuma]

Considering "Extended Illusions", the Shadowcraft age class ability, explicitly goes out of its way to say it stacks with Extend Spell, I doubt it.

They would have said something if you could stack them.

[PinkysBrain]

Stacks with persistent spell though.

[Matamane]

Good enough

[Sstoopidtallkid]

There's also certain class features and abilities that can increase duration for some spells. What do you want double-extended?