For A-OK, your only option at this time is to create a new device called something like “All My Shades” and then pair that device to every shade manually.
In the future we might make it possible to associate that “master channel” with a Group in the app, achieving popcorn-free groups and state updates on the individual devices, but with extra upfront work. Theoretically we could have some kind of wizard for the pairing process but that gets rather complex. Thus far this has just been too complicated for us to justify implementing, but let us know how important it is for you (and others).
Thanks your reply, I was not aware it was possible to pair more than one shade to a ‘device’ in the App. This works much better than groups, due to no popcorn and direct operation from Hubitat (which doesn’t seem to support groups).