This idea should be thought in future by the Outsystems developers. The Service Studio must provide the ability to debug a multi-tenant application some how. I remember that we cannot even 'Run' it. Besides, if we have lot's of tenants, testing a query it's not that easy, since we have to find in a long list the right tenant to test some values.
At this moment, this is a setback which must really be improved. I'm positive that someone will think about this in near future.