We looked at REP-140-142 (ad hoc report writing functionality) in the Reporting SIG meeting today in the context of reports that use personal information, which would not be GDPR-compliant.
UXPROD-1873 covers REP-140, REP-141, and REP-142. I added a note about personal info and GDPR to UXPROD-1873, linked UXPROD-1873 to REP-140-142, then closed REP-140, REP-141, and REP-142.