I suspect that the whole sleep issue which is done to extend battery life is probably the reason the Pronto socket implementation does not have a "Listen for connections" function. To have that they would need to keep wifi always active ergo keep awake, and hence the battery would drain excessively.

It would be nice if Wi-Fi had a wake on Wifi but no matter how you slice it the receiver must be awake to hear the wake up call so the battery drains.