Simple RAW for 5e V: The Disadvantage Strikes Back

[Ortho]

Q313: It's generally accepted that metamagic can be applied to spells from scrolls. (There's even a Crawford tweet confirming it.)

Can the Quickened metamagic be applied to cast a spell from a scroll with a bonus action? Bearing in mind that the spell scroll description explicitly says "Casting the spell by reading the scroll requires the spell's normal casting time." [1] The question here is equivalent to asking which is the more specific rule here, the Quickened metamagic or the spell scroll description.

A313:
Metamagic is a specific exception to the general spellcasting rules. The text you've quoted from the spell scroll description just reaffirms that casting a spell from a scroll also adheres to the general spellcasting rules.

So Metamagic is more specific than the spell scroll rules, and you can indeed Quicken Metamagic a spell scroll.