I doubt people would use a synopsis field sensibly.
The readmore considerations are a nuisance, though; most aren't even long enough for me to feel a readmore is warranted. In some cases there is not a clearly discernable place to put the readmore, which would IMO require a content-level decision that's outside a janitor's purview.
Sadly, I think the only thing to be done is to encourage janitors to /msg the considerers as often as necessary
(something I need to do better at).