A report made by a user on a composite model dataset (dataset based on a dataset on which RLS is applied via UserPrincipalName(), and mixed with local files) is very slow.
More than 30 seconds to refresh visuals on Power BI sheet (Services & Desktop same).
Same report, with a role without RLS, filtered on a value of the mail column, which is used to apply RLS with UserPrincipalName() functionnality, has no performance issue. all visuals are refreshed minus than 5 seconds.
No more performance issue with same visuals and RLS, but directly on the dataset (no local files added).