Would this font's use be allowed via cufon on a website with current license, or would that require commercial licensure?

The license is clear: ... the copyright remains with Studio Kmzero, and you are not allowed to distribute renamed, edited or derivative works, either for profit or not. To acquire a complete license for commercial use (allowing file release to a prepress bureau and embedding in other software files, such as Portable Document Format (PDF) or Flash files), you can contact us at info@studiokmzero.com ...

Contact them I'd say ...