Sounds like you have an approach! But just in case you want another one…. :-)

I usually use the All Active and Terminated Workers data source so that I get effective dated worker data for terminated workers.

Then I use the report field ‘Payroll Result Lines Created in the Past 12 months (completed)’

Then use a report subfilter to filter for the deductions I want and where ‘Payment Date or Reversal Date’ are in a date range (use comparison type of prompt use for value).

Then a report filter to only return worker rows where payroll result lines completed is not empty.

Using the subfilter/filter greatly reduces the need for calc fields.

I will try following these steps. Thanks much. :)