Right now there are 2 primary was of achieving this without automation:
- Create new GameObject under the original object
- Reparent the new object under the same transform as the original object
- Reparent the original object under the proxy
-OR-
- Create new GameObject under the same root
- Copy the transform component of the object you'd like to be located under the proxy
- Apply the transform component to the proxy
- Reparent the original object under the proxy
Automation and ability to create proxies for multiple transforms at a time using macros would make it a lot easier and faster