When capturing the header information from the MS SQL transaction log, Qlik Replicate currently captures the field [Transaction ID] from the physical LDF TLOG file. There is another transaction id, however, called [XACT ID] in the TLOG file. The [XACT ID] is the transaction id that is available during the MS SQL transaction itself, and would be very valuable for mapping other events to the change event in Qlik Replicate.
In our use case, we capture the user logged into the application at the time of the change for auditing purposes. We log these using MS SQL's native SQL Audit. We need some common ID that can be captured during the SQL Audit that can be used to map to the change that is captured in Qlik Replicate. The transaction_id field that is available at the time of the SQL Audit is the [XACT ID] field in the LDF TLOG file. If Qlik Replicate just added this field to what they capture during CDC, then we could more easily join this data at a future time when we need to report out for an audit.
Here's a screenshot from MS SQL comparing the SQL Audit data (top) with the LDF TLOG file (bottom). Note: the [Transaction ID] value in the bottom set is used as the transaction__id in Qlik, though the bytes are reversed. (0000:113c53e1 becomes E1533C1100000000)