Back when preprocessor optimization data was displayed on the preview page, one could see the output of mw.log and mw.logObject calls in the LUA code there. Right now, I can't find any place when I can do that any longer. I know about the debug console, but that is populated only when you introduce something there and it's almost impossible to exactly reproduce the parameters generated by passing through 3 templates and 2 other module calls.
Thanks, Strainu