It's unlikely that Argons will ever be able to connect to hidden networks.
The reason for this is that the esp-at Wi-Fi firmware used on the Argon NCP does not have a way to connect to the best AP based on SSID. When a network has multiple APs with the same SSID, which is the normal configuration, it would only connect to the last AP by BSSID, even if it was out of range right now. To work around this, the Argon does a Wi-Fi scan first, finds the strongest RSSI for a given SSID, and connects to that. Because of this, it won't see hidden SSIDs, and thus will never connect to one.