I currently have an SP pool of around 1.6k even if at 20 seconds of channeling Perspective Distortion, 60 SP is absolutely nothing. Mind you Lv5 Split Arrow is 37 SP per cast, so 60 SP for a 20s channeling duration is way too SP efficient.
I also suggest posting this on the class feedback section or submit a ticket and report it instead of nagging me about this. I am not a developer or whatsoever.