Dual-Balanced and double weapons

[ShadowWalker]

When I apply Dual-Balanced to a double weapon, I expected the options to apply it twice. It only applied the cost once.
What's also interesting is if you have a character that has a proficiency in Dire Flail, a double weapon, and you apply Dual-Balanced to a Dire Flail the weapon shows as and has modifiers as not being proficient.
I also tried this in hlo, and although it doesn't allow for it to be taken twice, once for each part of the weapon, it doesn't make the character non-proficient in it.