[Fixed]-Can Django's development server route mutliple sites? If yes, how?

No, you can’t.

The SITE_ID is cached in various places, so you can’t change it at runtime. You need a separate process for each site, but you can’t bind more than one process to a single port. Neither can the development server act as a reverse proxy for separate processes.

Running each site on a different port is the closest you can get. This is what happens with any HTTP-based app server, but in a production environment you use a reverse proxy to forward all requests from port 80 to the appropriate port for that site.