At a recent project, we had a requirement to show the variables of a record producer on the change record that was created by the record producer. This can be done easily by adding the variable editor to the form.
However… the UI Policies and client scripts defined on the record producer cannot run on the produced record like you can do with Request Item variables.
The requirement of the client was to make the information of the variables available on the change record. Having the fields listed out in a change specific field was the next option the Client had for this requirement. The variables however needed to be listed in the same order as they appear on the record producer form. The functionality of a label and multiple checkboxes is used regularly, this should be visualized the same way in the record producer.
Another reason why the variable pool option did not make it was because the variable pool can only be used to get the label,value and type of a variable related to the change record. We needed more information from the variable, for example the order field.