The idea here is to package the SVS runtime too along with .VSA Archive. Also instead of .VSA, make it as a single self-executable .EXE / .COM file where all the runtime/ temporary files are sandboxed. The biggest plus of this approach is you need not depend up the presence of SVS runtime in every client machines & need not worry about any traces / leftovers. This approach will make all the existing Applications truly portable.

 May be virus infections can be bloced if somevalidation /check sum is verified before every execution.