OJS on MariaDB cluster?

We had migrated an existing OJS3 database (that was converted from a previous OJS2 installation) to a MariaDB Master/Slave server without any problems.

However, the migration to a MariaDB Galera cluster failed, because not every table has a primary key (which the script to migrate the database checked), which is a requirement according to https://mariadb.com/kb/en/library/mariadb-galera-cluster-known-limitations/ :

“All tables should have a primary key (multi-column primary keys are supported). DELETE operations are unsupported on tables without a primary key. Also, rows in tables without a primary key may appear in a different order on different nodes.”

Are there any plans to improve the database schema?