The fact that someone is on a connection that can't cope with long downloads in no way means that they might not have a great deal of relevant expertise, and have information about the provenance of songs that could be invaluable.

As for irrelevances, clearly these wouldn't belong in the edited notes page for a song (or whatever form it takes), that is going to be the part of the exercise that could demands considerable self-discipline.

But when it comes to a thread that is trying to gather the material which can later be edited, it's diffeent I'd suggest. It seems to me that excluding irrelevances is not going to be practical, and could even be less than desirable.

I suppose it would be possible to imagine some system in which people would volunteer to set up DTStudy threads, and have songs allocated to them - but I can't see that working. However when it came to editing the material something of that sort might be needed.