>The major problem is that some useful content gets shelved.

I don't really think that's a problem. We know when a thread has gone off topic. And "move a thread" is figurative. Also, there is precedent, so it's not like the UT would be breaking new ground. But, it's just a suggestion.

> We would also have another line to draw [where?]. The UT has already drawn lines, I don't see why this presents more of an issue.

>Then there is the hazard of, "You moved my thread, but you didn't move Billy's thread. You just don't like me." With apologies to anyone named Billy.

With all due respect, yes, whatever rules there are would have to be evenly applied.