Since mining is not allowed in this current version of steemd, mining an account is not possible now. Starting with 0.20.0 it should be possible but I don't know if it would be used like the initial setup (that I know too, very well) or it would be different. From what I saw on GitHub seems like mining will produce some tokens (different from STEEM) that would be "good" only for account creation. In this scenario, the token holder must exist, so an account can't be "mined into existence".

I'll keep an eye on the GitHub and let you know.