ReadyAPI: Multiple Target URLs

We need the ability to run a single ReadyAPI Performance test against multiple copies of the same web application deployed to different URLs in order to see if one deployment under heavy load affects another. In other words, multiple environments being tested in parallel as part of the same load test. Has anyone run into the scenario before and if so how did you approach it?

As a quick test, we can run multiple instances of ReadyAPI from multiple different machines, but that does not scale well if we want to eventually test more deployments and have for example 10 different URLs in a single test. It would also be quite expensive to get full licenses for each ReadyAPI instance and separate VMs to run each instance of ReadyAPI.

My current plan is to attempt to rewrite the APIs we have currently to parameterize the second part of the URL in a groovy script and base it on the load agent name. That way we can have up to one URL per load agent, as long as all URLs share the same base host.