I just noticed that my box has received a software update.
Software version: UKSFAA 3.00.77
Update date: 26 JUN 2017
(That's the date of the software, not the date my box received the update on.)
I don't know what the changes are in this software version, except I did notice in the TV guide that some currently-on-air programmes are displaying a new icon which, upon closer inspection, allows me to watch the programme from the start (even though it's still on air, and I'm not recording it; clearly this is using iPlayer/equivalent).
Currently it only seems to be BBC and S4C channels which are showing programmes with this option.