For systems that support read replicas (e.g. AWS RDS with read replica, or Aurora built-in), there may or may not be a performance increase if read-only queries could be off-loaded to the read replica instead of the primary RW. Don't know how much this makes a difference but may be worth testing. It could also help with maintenance modes for backups or restores.

Configuration would be simple, hibernate properties would have an optional read-only connection, and if not defined, the read pool would just point to the normal one. The api would need major changes to support it, but it could start small.