Scroll Mastery can be taken twice (or more)

[maddong]

Eg Cleric and Artificer

[Archangel_666]

Wand And Scroll Mastery: +25%/+50%/+75% to the effectiveness of your wands, scrolls, and other items that cast spells.

Tier 1: +25%

Tier 2: +50%

Tier 3: +75%

So yes, they can be taken more than once. This is by design. What's your point exactly?