I think there have been some Super 16 HD shows, on ITV at least, if not the BBC.
There's been 2-perf 35mm ones as well. I saw some outtakes from one of the Royle Family specials which shows it was filmed that way.
I think one of the early BBC HD film productions (The 39 Steps?) was 3-perf 35mm. (The BBC, at the time, were suggesting that 3-perf 35mm may be a better choice with a similar cost, instead of Super 16 ISTR)
It is kind of a moot point now - as most stuff is shot on Arri Alexa or similar digital movie cameras (Red, Venice, F65 etc.)