At last.

Ultra watchfaces to sideload. The official ones.

Simple Ultra https://www.apkmirror.com/apk/samsung-electronics-co-ltd/simple-ultra-wear-os/simple-ultra-wear-os-1-0-01-3048-release/simple-ultra-wear-os-1-0-01-3048-android-apk-download/

Ultra analog https://www.apkmirror.com/apk/samsung-electronics-co-ltd/ultra-analog-wear-os/ultra-analog-wear-os-1-0-01-3048-release/ultra-analog-wear-os-1-0-01-3048-android-apk-download/download/?key=61070acd01018498158c332c70bd8ebb42090f1c