My old rule still counts. you should be always be able to use the last package todo all updates at once!
You could even update an old vm2.6 with vm4, I think. Okey I did not try, but it should work. The process always updates directly to the last db layout, which is the main thing if you update. There are added some exceptions for problematic updates, but per version and so on. So of course do it first on a testserver, that is always better. But just use the last package and install it over.