So, assuming the following
-Sorcerer level 20
-Quicken Metamagic feat
-Maximize Metamagic feat
-Empower Metamagic feat
-Spell Perfection: Battering Blast
-Mythic tiers (Archmage)
-3 Path Abilities of Arcane Metamastery
Round Zero
-Swift action to activate Arcane Metamastery picking Maximize Metamagic
Round 1
-Apply Maximize metamagic with Arcane Metamastery (no change in casting time or spell slot)
-Apply Empower Metamagic with Spell Perfection (no change in casting time, spell slot would be 9 or less, no change in spell slot)
- Spell casts as a standard action level 3 slot
-Swift action
-Apply Quicken Spell with Spell Perfection (no change in spell slot but spell must end up as 9 or lower including quickens +4)
-Apply Maximize Metamagic with Arcane Metamastery (no change in casting time or spell slot)
-Apply Empower Metamagic: increases spell slot by 2, would make spell casting a full round action but quicken keeps it swift
-final spell slot is: 3 + 4 Quicken + 2 Empowered (Maximize does not count against)=9 so Spell Perfection can work and brings final slot down to 5
End result
1 round use a standard to cast Maximized Empowered Battering Blast for a level 3 slot, and again as a Swift action for a Quickened Maximized Empowered Battering Blast with a level 5 slot.
Is that the correct interpretation?