We have to setup 600 individual scan tasks which have all the same settings - same credentials, same exclude/include filters, same settings for everything, run once schedule disabled (they have to be pinged and then manually run based on availabilty and load bandwidth). The only thing that changes is the target machine and the scan crawler machine and everything else is same. In this way you can just select to create a task by template name, select target machine name and crawler and hit submit to queue the task in the list for manual start.
Rich