As a short answer, it is not possibl.
To elaborate, the architecture allows only one platform for the database support at any given time. When your second instance tries to claim the database, it sees an existing foreign ownership and denies it.
In theory, if there was a workaround for the ownership flag, the second problem is a lot more complex and unavoidable: the platform heavily relies on in-memory model of the system. For example, gets sets deletes on properties are stored in the DB but not read. Reads are done from in -memory. The only time the DB reads happen when things are restarted (and some other trivial use cases) - to rehydrate.