Thanks for the response!
I can confirm that 0.7.40 worked in creating the catalog. The error I saw uploading to the kindle previously also didn't reappear, I may have been confused with .39 given I was installing/uninstalling several times
The catalogs created weren't quite what I was expecting, not tying into the Kindle collection system, but rather being a book in it's own right with no way (it seems) to "click" one and go to the book itself.
After some research I've gone with using an app called the
Kindle Collection Manager to edit collections on the device, and making one Catalog with Calibre per collection (or for the larger collections anyway) which I can browse in each collection folder for more information on the books in it
Works nicely so far!