Maybe the best
thing to do is to "sign" the comments _for them_.
I.E., add an identifier to what people have written, primarily to keep
the comments straight.
That sounds like an excellent idea.
I've done that, especially when revisiting a talk page where I've contributed but
it's not clear who said what. I've also gone back and found old (but still
relevant) dialogue and put lines or indentations between unsigned paragraphs and my
own--most recently, on [[talk:Mumia Abu Jamal]]. I did not write the first paragraph; and
I think making that clear is both acceptable & preferable.