Where does Apple store Maps Guides data? Is there a way to back it up?

Does anyone know if there is a way to create a backup of one's Guides? Or, at the very least, where the Guides file/files are stored? I've now had an update to iOS 15 and a test installation of macOS Monterey (12.1, no less) bork my list of Guides in Apple Maps. I was lucky enough that, both times, I was able to reconstruct them from a device that was offline but still had the guides cached. I would like to upgrade to Monterey at some point, but I don't want to go through the pain of recreating my Guides again, one item at a time. I have several Guides, many of which have 50+ entries, so it would be a considerable pain to do this. It occurred to me that Apple must be storing the data somewhere in iCloud in order to sync the Guides, but I can't find it. I've looked through

~/Library/Mobile Documents/

, but I don't see anything that fits the bill. I've also looked online to see if anyone has described where in iCloud the Guides / Maps data are saved to, and I've tried searching for developer documentation relating to a Guides API or explanation of the structure, but I haven't found anything relevant thus far…