It could probably be 10%, I was on the fence about it eclipsing aetherflow. I think it's important to have a way to dump aetherflow productively because encouraging overcapping is at odds with the design for all the other jobs - you don't want to overcap mp on drk, you don't want to overcap beast gauge on war or cartridges or samurai stickers or whatever.

I think your maths is off. I'll go and test it myself, but from looking at a couple of parses it seems that energy drain's closer to 3-4% contribution even without exclusive use on ED. According to some calculations on the yedlihlad beach, energy drain is about 4.8% of my damage if I burn all aetherflow + dissipations on it and use it under chain. Energy drain doing 3149-6494 (3426 median), which was about 267dps/5525dps or 4.8..%. I did forget to use dissipation toward the end, so should probably have had marginally more.
Sorry for the delay, took ages to add up all those numbers from the flying text