It does use browser storage which will disappear if you clear the site data, but you can also download to a .JSON file, which you can import again later, or on a different device.
Maybe not the best solution, but if you and your players use the Google Drive app to sync files, you could just edit them locally and they would update automatically. Maybe. Haven't tried it out. Regardless, best of luck to you!
Yeah, the intent of this project was to mimic the DURF sheet, so it's not designed to be modular or customizable. A character sheet creator tool is a neat idea, though.
