The other option is to do what that page suggests, migrate existing profile to chatmail or a dedicated address (How to migrate your profile to another relay (version 2.33) now has a footnote about migrating to non-chatmail address if you don’t like chatmail for some reason) and create a new profile on the old address, but then this new profile will have no history of your email chats as it will remain in the “encrypted chatting” profile.
What is the best option depends on how you use Delta Chat now.