Flutterby™! : So if my view is over the NSScrollView

So if my view is over the NSScrollView stack, it gets its -mouseMoved: events just fine, if an instance of that view is over a WKWebView (with innocuous static content), it gets weird hiccups, where the events drop out for a second or two occasionally.

(Trying to recreate in a stand-alone app the thing where the scroll view drag is getting interrupted by other views.)

Edit: Well, and now it's not doing the herky jerky thing. Computing was a mistake.