Vitess table equivalence configuration

We are trying to use table equivalence feature in vitess 9.0.0 as described here .

We have sharded and unsharded keyspaces. Tables from the unsharded keyspace are copied as reference tables to the sharded one using Materialize workflow. The application connects to database via VTGate without specifying any keyspace - is uses routing rules to find destination tables. In order to use local joins to reference tables when querying a sharded table we set routing rules as described in link above:

{
    "from_table": "product",
    "to_tables": ["sharded_keyspace.product", "unsharded_keyspace.product"]
}

The issues we are facing are:

1. This routing configuration conflicts with a "standard" routing configuration, and vitess shows error "table %v has more than one target".
2. It seems the configuration is ignored (when no keyspace specified) and joins on reference tables are still scattered.

How do I configure routing to be able to use advantages of table-equivalence?

Thanks in advance.

Recieved an answer from developers that the feature is deprecated. It will be removed from the documentation soon.