If you are developing for EP and creating/modifying web controls. You would notice that changes you make in Visual Studio will be published in USR layer. To start visual studio in some other layer, create a Visual Studio shortcut > Right Click > Properties and set target to something like this:
"C:\Program Files (x86)\Microsoft Visual Studio 12.0\Common7\IDE\devenv.exe" /AxConfig "C:\AXCU8_DEV10_VAR.axc"
The highlighted text is basically pointing to the AX configuration file for VAR, CUS layer.
"C:\Program Files (x86)\Microsoft Visual Studio 12.0\Common7\IDE\devenv.exe" /AxConfig "C:\AXCU8_DEV10_VAR.axc"
The highlighted text is basically pointing to the AX configuration file for VAR, CUS layer.
