In the spirit of documenting my journey, I’ve run across a post for a similar tool that looks like I may get away with classic and some caveats.
jdstrand outlines that the home and removable-media plugs would allow access to .scuttle.json files that aren’t in the top level of $HOME. Which does work as advertised. I think with that little nugget we can close this topic, and I’ll progress forward with the classic security model and document the caveats due to the security model of snaps.