This was announced 4 weeks ago.
But my box is stuck on 14.1. I have tried maintaince mode and it still stays on 14.1. I am still on the post beta trial. I can get it by changing my feedback group policy in settings. But when I did that before I couldn't boot into maintaince mode. I got the 'Boot fail Invalid Signature'. Which meant I got a replacement box.
Yes, the BT release is still 14.1.0, 1.7.2, 392, 29.
The important bit is the 29 for Extra channels (rather than 28).
We are waiting and hoping for a BT release which includes recording the Internet channels.
Youview have stated that the software releases should converge again, so hopefully the next release from them incorporating IPTV Recording will get sent out to all Humax devices (BT or otherwise).