There is no feature in SharePlex that would allow only committed data to be replicated. To reduce latency at the target, SharePlex replicates changes from source without waiting for COMMITs. For the most part this is advantageous as most applications will have a very small proportion of rollback transactions relative to the total number of transactions processed.
Only when transactions are rolled back, extra work is involved on the part of SharePlex to then send those rollbacks to the target as well. This can slow down replication somewhat. However, this is a small price to pay for the gain in speed that is achieved with the replication of normal (non-rollback) transactions.