Or you can simply use my map starting tool (MS.exe) that is included with ET Mapping IDE.MS.exe
Set your hotkey in MScfg.ini for fast map reloading.
If your ET is already open then you can reload your current map just by pressing the hotkey.
Args line in MS.exe means additional parameters.
I usually use these args: +con_drawnotify 1 +developer 1
Use MS.exe in combination with etmin.exe (Hotkey: Alt + Z)
When you do some updates in Radiant, keep your ET open and minimized
and when you need to test just compile your map,
press MS.exe hotkey and maximize your ET with Alt +Z for fastest possible testing!