How can I download clip collections?
Great to discover you're working on making the process easier for online-only content, dinky. I'm sure I'll make good use of it.

Does anyone know of a technique to similarly get a list of pids for clips?

This would be particularly useful if, for example, you wanted to download your favourite performances from The Voice UK (when it was on the BBC) or your favourite dances from Strictly Come Dancing. I've just checked the SCD clips; at the time of writing there's 94 pages of them with a total of  2,242 clips—you'd have to be pretty dedicated to copy these urls manually.

Life was so much simpler before the BBC stopped making their programme xml and rdf data available ☹️
Try youtube-dl