I see there is one more place in line 2539 where ignoreJobProgress is set to true:
// JM 2018-09-24: If this is the first job added
// We always ignore job progress by default.
if (jobs.isEmpty() && preview == false)
ignoreJobProgress = true;
So that's probably related to your warning... I'll ask Wolfgang if he can look into this since he's currently refactoring the capture code.