[Toffee]

I'm playing a Destiny Rogue with main-class Engineer and subclass Spellthief. I also have a Dar'Ensha Plus equipped and have noticed that, while my Rogue skills receive the -10% FP cost, both of my skills for my promoted classes aren't discounted at all. Every engineer robot costs the same 50 FP in both the skill list, hotbar previews, and the FP bar itself (I triple-checked to make sure it wasn't just the skill previews). Spellthief skills also cost the same, meaning that my promoted classes aren't being discounted at all.