Usecases:
1) I want to run separate scratch builds per arch from the same big srpm. To not upload it many times I can reuse existing srpm. (simple getTaskInfo(request=True)['request'][0] works for scratch builds, scratch task id is an input)
2) I want to run scratch build from already built content for different target/arch (currently I need to download srpm and upload it back) (nvr is an input)