Well yes I can see it is advertised as having Auracast. I have looked all through the user handbook that came with mine (which I bought only a month ago with my new Vivias) and there is no mention of Auracast though.
It’s very hard to see from the video in that Resound advert what the guy is doing, but I can’t find anything similar with the Resound Smart 3D app for iPhone. There is a slider for Auracast Assistant, but that is something else - nothing to do with the Multimic +. The user handbook mentions unicasting to several users, so that is where the Multimic + is paired with more than one pair of hearing aids and sending them audio at the same time, but it doesn’t call it Auracast. And true Auracast doesn’t need any pairing.
I wonder whether Resound hasn’t enabled Auracasting from the Multimic + yet. Or originally enabled it originally but doesn’t now.
Maybe someone else who has a Multimic + can add to this and explain what is and isn’t possible.