Local does not mean encrypted
Browser storage belongs to the current origin and browser profile, but it is not a secure vault. Anyone with access to that profile or device may be able to access its site data.
Persistence is a request
The browser may grant persistent storage, but policies differ. Users can clear site data, storage pressure can affect non-persistent data, and private sessions may discard everything when closed.
Export project backups
Use Save project to download a portable .lipiproject backup containing the verified source font and saved designs. Import that file later to continue in another browser or after clearing site data.
A new reference means a new project
Each project is tied to the SHA-256 identity of one static source TTF. Choosing a different reference font opens a separate project so its glyph IDs and shaping structures cannot silently replace those of the current project.