Philocetes, I'm all for expanding the boundaries of knowledge and whilst my knowledge is skewed to the scientific, I can't recall any recent Listener theme that required anything above a basic grasp of any of science's constituent subjects. Yes, the "Trailblazer" was known to me, though not the detail of the tale. However, to find the level of detail required to complete the puzzle, I read the text, which was not, lets say, something I would choose to do again - not a literary classic, to my eyes anyway.
Now the internet, then themes are easier to track down and have taken some of the fun away from - flicking through the reference section and seeing what other random information one picks up is a thing of the past. Though, having said that, our new central library is book-light and computer-heavy
The Listener has created rules to constrain its puzzles, which I would certainly argue against, but with those in place I really think it should follow them. There are times when I do think that the puzzle that is regarded as the pinnacle of the published puzzle would benefit from a return to a more liberal attitude to its puzzles, where failure is more common. Apologies, for my criticism, it was certainly not provoked by the clueing or construction of the puzzle, just my reaction to reading, what I consider to be, a poor piece of empire-esque prose. Give me Euripides, accompanied by Beethoven anyday.