You're welcome.
Two further thoughts:
1) This has no use when not running a load test, so a separate test step might be confusing for the user. I wonder if it should be a property (or properties) of existing test steps which would only 'activate' during load testing.
On the other hand, a separate step could have an option to fail the test case if the required threads do not enter before the timeout...
2) How best to handle load test strategies where the number of threads changes during the run? For example, if this was configured to wait for 5 threads but the number running drops below 5, the effect would be to delay all threads by the timeout value.
