A common mutli-tenant scenario involves using model that only differs by schema. Currently this requires a different model for each tenant. If the model could be parameterized somehow so that the schema used is different depending on the context/connection/tenantid/etc, then this could allow the same model to be used for multiple tenants, which would also mean that needing to change the model cache key would not be needed. We should also consider how this interacts with reverse engineering and migrations. See #9864 for a particular case where this could be useful.