Hi! You can always annotate multiple projects with different types of annotation types in parallel if you start separate instances of Prodigy, e.g. on different hosts/ports. Each instance will then hold its own state, database connection, session management etc.
I've explained a bit more about this in the following thread, including why switching between interfaces in a single instance via the UI is something that really only works in a demo and isn't a good fit for a real-world workflow: