Me personally, if I do have need to drop old threads, I decide based on age and also whether they still have anywhere to go. If it feels like most of the potential's already been tapped, I feel better about letting it go.
Thing is, I am really bad at judging if things still have places to go or not. And with clean slating I worry that I am over looking with things to go.
you probably arent actually that bad at judging it, you just understandably like the threads you have going with people and dont want to disappoint anyone
and thats a valid worry, but in a hobby based in collaboration we have to trust that our friends are doing their part in the collab by communicating with us when they need more from us!
yeah just put a message out on plurk to say "I'm going to clean slate, so if there's anything you want to hash out how it would have ended, let's do that here"
the source could be different but the effect is still the same