I would like to compile .mxml only with mxmlc -load-config+=myConfig.xml.

Is it the only way to check No output, only run pre/post build commands in Project properties, and then to put mxmlc -load-config+=myConfig.xml in Pre-build command line, or is there some other way?

Thanks.

You could always compile via a bat file, something like this:

set flexpath="C:\sdks\flex\4.6\bin"
set isDebug=false

%flexpath%\mxmlc -load-config+=MainConfig.xml -incremental=false -benchmark=false -o YOURProject\trunk\bin\Main.swf