So, there is actually a TransactionSubType for "Modified via patron aging job" (336) that is associated with the "Patron registration modified" TransactionType (2003)... Seems like someone was already expecting someone would be interested in tracking/reporting on this! I don't know where you stand with SQL, but you can plug this into the SQL Search for Patron Records and create a Patron Record Set with the results:

SELECT [PatronID]

FROM [PolarisTransactions].[Polaris].[TransactionHeaders] AS h

LEFT JOIN (SELECT [TransactionID], [numValue] AS [PatronID]
FROM [PolarisTransactions].[Polaris].[TransactionDetails]
WHERE [TransactionSubTypeID] = 6
) AS d1
ON d1.[TransactionID] = h.[TransactionID]

LEFT JOIN (SELECT [TransactionID], [numValue] AS [PatronAssignedBranchID]
FROM [PolarisTransactions].[Polaris].[TransactionDetails]
WHERE [TransactionSubTypeID] = 123
) AS d2
ON d2.[TransactionID] = h.[TransactionID]

INNER JOIN (SELECT [TransactionID], [numValue] AS [AgingBoolean]
FROM [PolarisTransactions].[Polaris].[TransactionDetails]
WHERE [TransactionSubTypeID] = 336
AND [numValue] = 1
) AS d3
ON d3.[TransactionID] = h.[TransactionID]

WHERE [TransactionTypeID] = 2003
AND [PatronAssignedBranchID] IN (BranchIDs)

Replace the BranchIDs with whatever branches you want or remove that AND statement altogether and you should be able to get what you're looking for. Of course, if you're comfortable digging into the SQL a little more, it's not difficult to connect data from the PatronRegistration table to get a real report. But a standard report delivered via SSRS for staff that aren't comfortable with SQL would still be nice.