At 99.70% accuracy you're going to start missing stuff. Champions now have a built-in 10% defense.
EDIT: Also, you left FM out of the AOE priority list. If its damage is good enough to throw in for single-target fights, it's amazing for AOE. Definitely better than Sweeping Blasters.
Thx I will edit in FM for AoE, forgot about that! I don't always use it (unless I have TSO) cuz it's not as heat efficient as Sweeping Blasters, but it's worth adding for sure. As far as acc goes, 99.7% ranged and 109.7% tech won't miss (I will edit in the tech %), you can see this from the parse posted in OP. Only the offhand hits miss sometimes and those are very minor.