Is it possible to see when a given view’s visible_region changes?

Also, is it possible for view.find(…) to take an optional “toPosition” argument, to limit the extents being searched?

The gist of these two questions are for the word_highlight package, which tends to bog down on “large” files (multi-megabyte). If only the currently visible text was scanned, it could be a lot faster. I can imagine a couple ways of working around it, but having the above two abilities would make this a lot simpler.