Change in Batch Delete members function

In the control panel, there is currently a function to batch delete members. The members to be deleted can be filtered based on the Join Date being older than a certain number of days. I can see the value in this remaining but I would like the option to choose by the Last Visit date instead. We have some users in the forum that log in and read but do not post. I would not want to delete their accounts just because their join date is old and they have no posts. I cannot use the unverified account option to prevent their accounts from being deleted because the dormant accounts that I want to delete would have been verified.