Tableau released multiple table storage feature as part of 2018.3 release. This feature is a game changer for row level security with base table and entitlement table. However 2018.3 has a small bug (#831080) that causes multiple table extract disabled when data source filter used. I am so glad that this bug was fixed by 2018.3.1 release!!! Today I tested and confirmed that it worked in Desktop.
Data source filter is common approach for row level security.
Nice, thanks for sharing Mark!