[Technologist]

What was interesting as well is during the mute Calendar North, subtitles didn't show either. Would they be being done live from the broadcast, that seems unlikely.

Subtitles are done using the studio output sound …….
Let’s assume that it is taken at the input to code and mux ,
And the OC47 (teletext) can be reinserted at that point on the region output
If the subtitler is near C&M site and its connectivity …. Is easy
If the are remote like at home it just needs a fast codec like Apt-X …
In the good old days of analogue that was noticeably faster as 4ms than the NICAM 16 or 32ms
Which was the back up,!