In the case of the screenshot attached, a single page down should do. When the screen is long, and the position of the sought for text is not known, do a loop of page down, capture text & instring.
It does scroll for some things, but not all. I always assume that it won't and I do explicit scrolling, similar to what Joe talks about. I do that because I KNOW that the method will work, where autoscrolling seems to be spotty.