RSBDCBTC uses some system commands that "break" current transaction/job so not suitable to keep control.
Hint: Better build a wrapper report, that will submite RSBDCSUB (so execution in another job) in sequence and then wait until BDC status changed (APQI-QSTATE, 'F' finished or 'E' error) or APQI record get deleted)
Regards,
Raymond