Yes, to get that effect you need to have a surface that has a image of a sky as it's texture and either override the panels outside surface or make sure that the material used for the panel uses the surface. For a good result you need to set texture size wide/high enough to the entire facade curtainwall or else you will have repetition.
It is already what I had been doing as a 'workaround'. I guess it is not a work around if there is nothing to work around, 😉 the way I interpreted the new texture feature was that there was an auto sky reflection on translucent surfaces, guess not!
I think then I need to find a better sky texture to improve the appearance of it 🙂