I tried asynch vi with TestStand 2013 and LabVIEW 2013 and it worked just fine.
When disabled "Automatically Wait for the Thread to Complete at the End of the Current Sequence", it did not wait for my case.
The execution of TestStand sequence file will not end till the step completes the execution. Hence, if you have an async VI in MainSequence, then, you might feel that, it is waiting at end of the MainSequence.
If you have another sequence containing async VI step and if you call this new sequence from MainSequence, we can see that, execution does not wait for async VI to complete at the end of new sequence, but waits at the end of MainSequence.
Can you share your files with the specified behavior?
- Shashidhar