RAW Power 3 will maintain its file browser feature set, and add the ability to browse Apple Photos Libraries as well. Ratings and flags will be stored in a small database, but I plan to add an export function to save the data out to a XMP file or something like that. I think it’s fine to use Photos as a repository for the whole library, with iCloud Photos. It does incur a monthly cost (I have a 1TB plan), with the associated benefits that come with a cloud-based library. I don’t think it’s clunky – the basic idea is quite seamless. I think if one manages multiple storage locations (file system + a library with exported JPEGs, etc), then it gets complicated quite quickly.