Hey @d_keith,
I am briefly on vacation, so it will probably take a week before I can have a look. But you are in good hands with the rest of the SDK team 🙂 But, yes, you should be able to create a repo (i.e., asset database) with CreateRepositoryFromUrl and when the passed URL already contains a repo, it should not create a new one. That was at least its S26 behavior, it could be that Tilo has changed that since then. If I remember correctly, Daniel reported something similar about that function not expecting existing repos, or at least that it created a database asset each time for being called (not the same as an entire new repo and probably what you mean).
The TLDR aside from the concrete support case is: Please create tickets for bugs, when the documentation says one thing, and the function does another thing, this is at least worthy of being a bug candidate. When this is super urgent for you and Ilia or Maxime do not have an answer right away, you could also ask Tilo or talk with Daniel what he did.