Unveil when visible for specified amount of time

[plaa]

I have a page with a long list of images that I'm hoping to lazy-load. The problem is that if I quickly scroll through the page, unveil starts loading all of the images at once.

What I'd want to do is to load the images when they have been visible on-screen for 500 ms (i.e. the user has stopped scrolling at that position). Is this possible with the current library?