Another Echoing Spell / Spell Perfection question

[Axebeard]

If you use Spell Perfection to spontaneously apply Echoing Spell to a spell, can you use it to spontaneously apply a different metamagic feat to its second casting?

So, for example:

Persistent Slow + Echoing Spell (Effective level 8)
followed by
Persistent Slow + Quicken Spell (Effective level 9)

Is that legit?