Move a small but varied photo set into Ente, including videos, albums, metadata, and files from more than one device. Check automatic backup and sync, then download originals and compare counts, dates, and checksums with the source. Try account recovery on a clean device using the recovery materials you intend to keep.
End-to-end encryption is useful only if you can recover access. Keep an independent local backup until restore and export have been proven. Test sharing permissions separately from personal storage.