Issues detecting above, below, and fully when scrolling fast past a 100vh item

[weotch]

If you are tracking a 100vh item and you scroll from it being below to above the viewport fast, IntersectionObserver doesn't update the handler at all ... like it can miss responding to the scroll even with a threshold that includes 1.

I may need to add a scroll event listener when in viewport to track these things ... do I bring scrollMonitor back for this? Or maybe scroll mediator?