Being restricted to just using username () in measures (or AllowedRowsExpression) means that you cannot use the context of the current user in slicers or page level or report level filters. Just ...
We very much need this. This would allow us to provide security and context for many of our visuals. The role based RLS is not scalable when you have thousands of employees also the RLS data already lives in our database we just need to pass it the current user to retrieve data they are authorized to see. Another issue is often this data is sources from transactional finance tables with millions of rows. Pulling down the whole table then applying Power BI RLS after the fact is often again not practical.
