In the community forums of Huawei UK, a user by Phil_Black revealed that a Beta Health App is live on the Chinese Huawei site. It is in this app that users have access to creating and adding new watch faces to the Huawei Watch GT.
Logging into the site and getting access into the beta version of the app, however, does need a Chinese Huawei ID which requires a Chinese number.
Once you have the beta version of the app, you can uninstall the current health app and install the beta version. From there, there’s a guide to creating a face and adding it to DCIM via the hi-suite desktop.
The new beta app then allows to add the new face and selecting it from the DCIM folder