Hi @robertmerrill,
The full desktop app will need to be installed by a user with administrative privileges. Once it has been, it will be available to all users. This is mostly because there are shell extensions and filesystem events that need to be installed.
It is possible to install the odrive sync agent/CLI without any administrative privileges: https://docs.odrive.com/docs/odrive-sync-agent
I actually created a little context-menu add-in that could be used alongside this. It was originally to provide better feedback for screen readers, but it could be used with the CLI to provide some of the context menu options for syncing and unsyncing: Sync All for users with screenreaders (for users with visual impairment / blindness)