No doubt an important factor. But like so many, how do we actually get the info. Do we get the trainer to do a daily report? How will they actually know? A bit like feed regimes, beach training. Do we require all sorts of info to make decisions. For some, no matter how much info is given out, it won't make any difference. Yet there is a cost in providing a lot of it. And things like sleep is a measure that is likely going to be subjective as we can't really ask the horse.
My view on getting an edge often relates more to determining what other punters think is important for a horse that you don't think is as important - or vice versa. If punters think the same thing about some aspect of form, it is hardly likely to lead to them having an edge.