As an aside...
You can create conditions in EG process flows to control the order of execution with if/then/else logic. These EG process flow conditions can be based on macro variable values. So, storing the "missing value present" result in a macro variable would allow you to use it in a condition in an EG process flow. For example, if you wanted to use the point-and-click Export as a Step in Project task to export the data rather than code (some do, some don't), you could use the macro variable value (which would reflect whether missing values were present) to decide whether to run the task during a process flow or project run.
Note: EG process flow conditions are only applicable when executed in the context of EG. So, if you plan to execute outside of EG, you should stick with code to do the conditional logic. For programmers, the code is often easier anyway.
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