I think its presence in the Wiim app is primarily dependant on the device firmware. The “legacy” audio pro app didn’t have such an entry as their device firmware didn’t support it, and even when it could pick up WiiM devices, it didn’t show such WiiM features as their app wasn’t looking for it. The new audio pro app can’t connect to WiiM devices at all (although it sees them) and I don’t have any w gen audio pro speakers to check (I suspect nobody has gen w speakers yet).
Not seeing it on their site now