From a co's point of view, I will keep an eye on it if left on to keep up on depth around points or humps. It is to out of the way to keep watching for details like specific bushes, trees or rocks. But it does help, unless its an area I feel I know well if the boater ask if I want it I will request to leave it on.
And if it is being left on a co should understand how to adjust it, but ask the boater if its okay to change it. Part of being a co for most of us is to learn, and we wish to one day have a boat of our own. Using whats available to you on different boats means you get to see different brands/models great time to take advantage.