More editorial intervention

At this point in the reading, the novel seems to become increasingly action-oriented, and as readers I think we've become accustomed to the jumps in time and narration that Richardson is creating through the "editing" of the letters. As editorial intervention becomes more common, I think it might be important to keep ourselves aware of what this editing is doing for the story. Early on in this week's reading, a passage stuck out to me on account of its slightly slanted editorial tone. I've reproduced the passage below. I guess I'd be interested in looking at ideas of how this tone sets us up to approach Lovelace's letters. What exactly are the limits of what an editor of these letters should do, and does Richardson's "editor" cross these boundaries?

"Four letters are written by Mr Lovelace from the date of his last, giving the state of affairs between him and the lady, pretty much the same as in hers in the same period allowing for the humour in his; and for his resentments expressed with vehemence on her resolution to leave him, if her friends could be prevailed upon. A few extracts from them will only be given...
(After violent threatenings and vows of revenge, he says--)...
(Thus triumphing in his unpolite cruelty he says--)" (L 187.1-4, 601)