There is no way to control 3rd party integrations if the provider doesn't have 3rd party certification. Its a want these houses have not a need. Think about what would happen if the system failed to perform. The certification company would be taking all the risk on a system the installer / maintainer has no control over. I believe these integrations rely on engineer level access between them. Any installer doing this without the necessary protection is daft IMHO.
There is a 'guide' being worked on but the scope is so massive there is no time line if it ever sees the light of day.