I was thinking something even easier and possibly faster to parse. Since I need the views to flip BEFORE I cast a spell (blizzard, rain of fire, etc) it could not parse the text. It would have to detect that I was casting it - by detecting the button press for that macro. THEN the moment it is activated, sync up the screens and then click the single mouse and presto - channelling the AoEs. So really just on button press (the same one which also called the rain of fire) swap cameras. This is probably doable with just /script commands - embed the script and then /cast Rain of Fire for example - no LUA even needed!

This would not be needed for Hellfire as it is PbAoE and not targeted but I like where you are going with this.