I do a similar thing for those projects ( like papers ) that won’t be public while I’m developing them. I have a directory where I put modules and proto-packages that I dev .
This works great unless I forget to get rid of manifest.toml (with paths that only make sense on my dropbox account) before I put the modules out there when I publish. I learned this the hard way when someone tried to reproduce my results and failed thanks to a path in the manifest.