I have built a whip character. The goal of this character is size from enlarge person, increasing reach with long arm, and attacking everything within 45 feet reach using whirlwind attack. I have invested the feats to take improved whip mastery so I can now threaten with the whip equal to natural reach +5 feet. So medium is 10, and large is 15. What I am trying to figure out is if the long arm spell would add to this threatened reach making this threatened space medium 15 and large 20.
Your arms temporarily grow in length, increasing your reach with those limbs by 5 feet.
It says my reach increases, but not my natural reach. Does this distinction matter?