ParametersInterceptor.java fills the log with unneeded warnings such this:
Parameter [username] is not on the excludeParams list of patterns and will be appended to action!
The cause of the problem is that normally (when a POSTed value matches acceptParamNames, but not excludeParams), the isExcluded() method will be called, which logs every match and not-match.
The logging happens with the notifyDeveloper() method of the class, which logs as WARNING in devmode, and DEBUG if not.
I suppose to lower this always to DEBUG, and maybe the notifyDeveloper() method should even be gone.
have a nice day,