Some time ago I configured Photostructure on my Synology (with the amazing help of the author, @mceachen) and the most paindful part was rescuing my 1.5TB of photos from Google Photos. Takeout was very cumbersome to use and download 100+ files of 4gb, so ultimately resorted to paying a higher tier at Google Drive, using takeout Google Drive option and the sync to the NAS. I still don’t have a good method to keep everything in sync as Google Photos does not offer a viable option for a cloud-to-premises sync.