The path to the socket used for client-server communication is currently hardcoded in alfred and its complimentary daemons. This makes it hard to run two instances of alfred on the same machine without any kind of virtualization or containers.
An user may still want to use two alfred instances to create a test setup or connect a single machine two separated alfred data clouds without exchanging data between them.
Applied in revision 6c6a6f7.
Thanks! Simon