You can actually be the admin of a Ditto server regardless of which NIP-05 you set! For example, even though Henhouse.social is the NIP-05 I use, I'm also an admin of Ditto.pub (and have a NIP-05 there, too, that I can use switch between any time I wanted).
The downside of doing this is just that your posts won't show up in the local timeline (which filters for those with a NIP-05 that match the Ditto server domain). But if you don't care about then I think that you can do it today!