The new action button feature provides the possibility to start an integrator job and define ETL variables dynamically. Instead of choosing each variable value it would be much easier to choose one named range which contains two columns, first contains the ETL variable name and the second contains the value that it should have. Or two rows, first row contains the name and second contains the value (kind of like the attribute filter range).
This has two advantages. 1) You don't have to click 20 times when setting 10 variables -> you have everything in one range. 2) you only provide the variables in your range, which really should be given to the job. If you have e.g. a ETL variable which origin is groovy it will still be overwritten from the action button, since you cannot exclude it from the action button when "execution with parameters" is active.