Recently received a notification that I'd need to update my version in order to sync. Is there a straightforward way of updating the application besides redownloading, installing, etc? Also not clear how integration with existing notes, etc would be handled if I'm simply installing a new version.
Just re-run the install / upgrade script*. It will do all the work for you and your existing note data, plugins etc. will be preserved. The only requirement is that if Joplin is running when the script is run you will need to shut down and restart Joplin after the update so the new AppImage can take over.
* This assumes that you are using the official install script and not a third-party package.