Why does the magister have the Armor Proficiency (Medium) [Rogue Genius] as a bonus feat?

[FreezingWolf]

I was checking about the magister class and notived that they can get Armor proficiency (medium) as one of its bonus feats. But I dont understand what the point would be. Gaining proficiency on armor doesnt stop the casting penalty, the class would still incur when casting in medium armor, right? So what is the point? Does the magister also gain the capability of casting in heavier armor if he has the correct proficiency feat?

[Rysky]

Unless it says they do then no, but there’s plenty of ways to reduce ACP.

So to answer your question the point is for Magister’s that want to wear Medium Armor.

[RJGrady]

Some spells don't even have somatic components, and there are ways to reduce the ASF penalty.

[ShadowcatX]

It's niche but mithral breastplate. It's a light armor (so no asf for magister) but it needs medium proficiency to wear.

Eta: Dammit, baited by the necro.