Maybe it’s late to be suggesting this, but a Symbolic Link in the plugin presets folder on each of the computers, win and mac, seems to work fine here as a possible workaround, until this is changed.
If you link to the top level of a drive, or a top level folder, you can easily create folders or access folders anywhere, using the Organize Presets button. And read and write the plugin presets directly from and to the intended project folders.