Each asynchronous function started, starts in separate thread.
So in that example you will have 2 threads since 2 asynchronous functions
will be started, each with its own (different) script.
Export your spreadsheet as csv file, than import it to BAS as a resource and set it to use each line 1 time (it is default setting I think). That way each thread would take new line from your csv file in run mode or as compiled bot.
Now they are trying to blackmail us, and although the person did not provide any evidence, we still have to disable the site and roll out the update with database encryption earlier than planned. User safety is paramount. The site will return to work in 20-30 minutes. I apologize for the inconvenience.