Solus VM reseller features are available only for the VPS reselling service. If your host add you as a re seller in Solus VM then you can create or modify or delete VPS under the limited permission. I think if you can go with any host offering VPS reselling they might offer the same.
There isn't a huge amount of automation available in popular billing panels like WHMCS which is the main reason I believe. Up until the new release of solus a while ago, then was no end user API access but now there is which is pretty popular. I suspect we will see more VPS resellers shortly.