The purpose of syncing the SFDC Activity to the Gainsight Timeline is so that CSMs have visibility into the most up to date communication with the customer. Currently the integration sync runs every 24 hours out of the box and can’t be adjusted. If the sync only runs every 24 hours CSMs don’t really have the most up to date view of the customer.
Ideally, you could set up this sync like you do in Connectors 2.0 and schedule the frequency you’d like it to run. Less helpful would to have it run every 4 hours like the Gong integration does.