ZMF graphics documents from Zoner Callisto can only be opened in that software or Zoner Photo Studio, so this pretty much limits any kind of zmf conversion or exports. In case of zmf to crw conversion this would be export to a format used in Canon devices. Might not be perfect, especially if the original raw was not from Canon, but doable to a certain degree for sure.
s always, if you struggle with Zoner formats, it would be best to reach out to their support or online community and technical social networks.
Updated: August 11, 2023