Just a little update. I contacted OA Support about the use of smart watches. Here is the reply:
Hi john,
thank you for your message.
The following operating systems are supported:
Android: OS2 and higher
Apple: watchOS 6 and higher
Best,
Lisa
Best regards · Best regards
Outdooractive Support Team
So with regard to Android, there is a much better choice available than with VR which was limited to WearOS watches only.