You can downgrade ASE to an earlier version while there still are transaction records related to SQL statement replication in the log. If you downgrade to a version earlier than 15.0.2 ESD #3, Sybase recommends that you use the standard documented procedure to downgrade an ASE with replicated databases, including draining the transaction log. See the ASE Installation Guide.
ASE 15.0.3 provides the following downgrade support for Sybase Mirror Replication Agents version 15.0.2 ESD #3 and later:
Sybase Mirror Replication Agents continue to replicate data even if the log contains information for SQL statement replication.
When a Sybase Mirror Replication Agent reads a transaction containing SQL statement replication, it sends atomic modifications for that statement and ignores information related to SQL statement replication.