So you'd have to essentially be waiting about WoTLK Gold the half-second gap that it can be up to in order to be able to use this macro and utilize arcane power, which means it's an DPS loss by having to wait for that long, or you're going to use every single thing in the macaroni Arcane Missiles is going to explode without the use of arcane powers, and that's obviously unsuitable.

We use it after the second casting and you then do a hardcast and any other AV so it's possible to enter the macro.

The reason we use the palm after the second buy WoTLK Gold cast and not immediately in the beginning is due to the fact of arcane's potential, and also because it provides an additional 30% chance to get it crit.