I never used nameplates until I discovered the Aloft addon, which I now find indispensible, but I find it almost impossible to target an AoE when a lot of mobs are in the area I want to hit, as the nameplates aren't mouse-transparent.
The perfect solution would be to force the nameplates to hide while I'm targetting the AoE, and reshow after I've fired off the spell.
OK... I've figured out how to toggle off the nameplates and cast Blizzard by using the following macro...
...but the last "aloft show" toggles the nameplates right back on without waiting for Blizzard to finish channeling.
^works. I just have to run the macro again while channeling to toggle nameplates back on. Weeeeeeeeee!