iCloud is on my to-do list but not high on the list. Sorry. It is popular when new watches are released but otherwise I get far more requests for custom activity types, which is what I am working on now, and improved interval schedules, which are next on my to-do list. Mirroring live data to the iPhone screen is also much more popular.
I will get around to it one day, but I am partially holding fire because it is very fiddly to implement on the watch because "iCloud Drive" is not yet available on watchOS:
When I try to use FileManager.default.ubiquityIdentityToken on watchOS it always returns nil. This works just fine on iOS and macOS and it is the recommended way to check whether iCloud Drive is
stackoverflow.com
iCloud Drive allows apps to have a directory in the app that is replicated across all devices using that app. Without it the app needs to do a lot of fiddly manual synchronisation. And I really don't want to do that when Apple might make iCloud Drive available on watchOS in the future.
I am not optimistic that they will add iCloud Drive, but I do tend to slightly deprioritise features that Apple may make easier to implement in the future. For example translation into other languages is another feature that is requested far more than iCloud support but which I am holding fire on for several reasons, one of which is that Apple may make it much easier in the future.
The live translation feature in the AirPods Pro 3 makes me hope that some sort of auto-translate may come to apps in the future. It may not be completely automatic but there is a good chance that multi-language support could become a lot easier to implement.
So I don't want to spend a lot of time on iCloud support and language translation now when there are more requested features which are less likely to become easier to implement in the future.