My recollection seeing this palm in habitat at the 2006 Biennel in the DR, was our scaling step magote limestone cliffs with breathtaking views of the ocean. It grows on nearly pure limestone, very little soil or orgainic matter found. Yes, just like the C. ekmanii. I do not recall which issue (has to be Jan. 2007?), there was a detailed article in Palms about this species. Scott Zona may have been the author.
I suspect that this palm needs very, very good drainage from the habitat soil observations. It should be more salt tolerant than C. Eckmanii due to its exposure to salt spray. The cold tolerance is questionable. Its habitat is purely tropical probably never experiencing a low less than 50F. It must also be noted that many Coocothinax species endemic to Cuba and its tropical climate have proven to have a fair amount of cold tolerance relative to their native haunts.
Definitely a very slow palm! The towering pliable thin stems we saw in habitat had to be hundreds of years old.