I am sorry but no this is not possible. The Telerik Testing Framework is more than just a set of DLL's. It is also a set of browser extensions for executing tests in the browser. These extensions must be installed by our installer for them to be correctly registered with the browser. We also add DLL's to the GAC which are required during test execution.
Of course this also means it is not possible to try to have two versions of the Testing Framework at the same time.
the Telerik team