The general idea is to be able to set a starting point to where sync the data while adding a new connector: for example you may want to save up MARs and time by only syncing data from a specific point in time and after, maybe because that collection don't really need historical data and/or your applications only require a small subset of the whole table/database;

Something like a timeframe setting (either a static configuration with a calendar or dynamic based on analyzing the table/collection data before syncing it would be good) definitely improves the control over the data