I have this issue FB13432607 where watchOS synced iCloud contacts just grow and grow and grow: I'm currently over 9 GB of contacts with many duplicate entries. iOS, iPadOS and macOS are also syncing the same iCloud contact store, and they're not showing this issue.
I've been reporting feedback for some time, but then I thought, hey, I'm a developer, I can write a watchOS app!
After the initial elation and some quick prototyping (it's not a huge amount of code), I came to see that CNSaveRequest is NOT supported on watchOS, which means I can't delete my contacts. (The other option is nuclear: erase all data, restore and re-sync). So writing an app is out, due to lack of API access.
Which got me wondering: is my contact store growing because Apple also doesn't have an API to delete contacts on watchOS? If so, this is a huge issue.
Any ideas?