John, thanks for sharing your insight.
My thinking was not into the direction to give anyone access, but just the Davis station owners and may be they are also required to buy the Davis PC software, dump that purchase apart from the ID and key for upload and use Meteobridge (or alike) to upload to the Davis network. IMHO it would not put any harm to Davis and will ramp-up usage of their subscription based service, but it would need their willing to have a 3rd party involved.
From a technical perspective I doubt simulating an upload to their servers will be any challenge at all (even without docs) but I am not looking for beef with Davis. Anybody here having a good relationship to Davis who might support the idea?