This is super cool Michael @DharmaNode.
One thing to note, the 50% offsets on iOS tablet display a blank white screen for the duration of the scroll for most sections. It occurs when viewing in desktop (horizontal) or tablet view (vertical). I think that is maybe due to the VH iOS bug? Not sure, and not even sure it is due to the offsets?? Just a faint memory of an issue I have encountered before and I think that was it. If I scroll very slowly on tablet, sometimes the images will display.
I will be able to play with the offsets and test later in the week. Wish I had more time now.