I think your question has more to do with how qRules is used.
When you use qRules, you are setting the Command node to one of the qRules commands. This generates a value in Result. You can use rules to place that Result anywhere you need it.
Then you execute another command, that is, you set the Command node to some other qRules command. Then this returns another value in Result, and you can use rules to place that Result elsewhere in the form.
So yes, the qRules secondary data source remains locked - it is locked in the sample form too. If you need extra fields, you add them in the main data source.
Hope this helps.