MetaTrader 4 has a very nice feature to quickly switch between their main program and their editor: simply press F4 on the keyboard.

Though this doesn't sound like much, it's a very handy feature when programming since in MetaTrader you press F5 for compiling, and then press F4 to directly jump to the main window to see how the programmed code works. If it doesn't work as expected or you made an error, you press F4 again and jump to the editor.

This is a very useful feature, since it makes coding something that much quicker if you can quickly flip between these two windows instead of having to use Alt - Tab to search the window between all your open windows or leave the keyboard and grab the mouse.
 
Suggestion: make F4 or F5 the MultiCharts 'flip' key, so that after compiling in the PowerLanguage Editor with F3, we can directly jump to MultiCharts when pressing one of these keys. Then, if it doesn't work as expected, we can press the 'flip' key again and jump directly to the PowerLanguage Editor.