Some really interesting points come up at proof-reading stage.
For instance, some writers are worried by changed formatting. Publishers often have change formatting either because writers have not adhered to either a set formatting style or the formatting style the publishing company requires. Also, manuscripts tend to be submitted ragged right but books are published with block text. This means that sometimes you words spread across a line. This happens in almost every book – except in a few children’s where the text is set either ragged right to aid continuity for less experienced readers – the eye can follow the text more easily – or where the text has been set so as not to have words dripping over lines. The latter can lead to lines being very spread out and looking clumsy. The odd thing is, most readers only notice words have been split across lines it when it happens to their work. But it is there everywhere.
Often one doesn’t notice until design stage that the writer has a quirk – for example putting too many speeches ending in “…” a lot. We then realise we do need to address this. When we make such last minute alterations the writers often don’t notice.
The final proof stage is never the time to make massive alterations. These should have been made ages ago in former edits. It is tempting, though, for writers to do this: they continue to grow and if they haven’t seen their text for a while they may be tempted to twiddle. Final proof stage is the time for abandonment. Leave the new ideas for the next piece.