There’s been a few threads about this (and similar) topics relating to animations appearing late/too late on scroll. Or, the inability to control where it happens. I can see this was flagged up for development in December 2017,
We’re trying to get Sections to appear earlier when scrolling - at the moment, they appear roughly when 50% down the page or when much of the element is visible. This leads to a (very) large blank screen waiting for content to appear.
Is there a work-around/method/fix for this beyond the increasingly more-common response of ‘beyond the scope of our support’/ we can offer paid development / we will add this request to our features?