My recommendation is to create 2 line items 'Filter for New Items' and 'Snapshot' in the system module (Dimension by the list).
Put 'Not Snapshot' as a formula for 'Filter for New Items'
Create an import action to copy the information from 'Filter for New Items' to 'Not Snapshot'. Note: Saved view should have a filter on 'Filter for New Items' as true. Then include this action at the first in the process which updates the list.