I have to test further on one of my own sites, but out of the box what you’re describing isn’t going to work.
All the items in a dynlist will get the interaction, the same interaction. So the only thing that would make them appeared deayed would be an onscroll trigger with the item place at different heights, but that’s not possible either.
So yes, you are right, you’d need to use different dynlists wit different sorting, to make it work. This is acceptable as a solution, IMHO. You can put quite a lot of dynlists on a page. I already do this to make complex grids. Such as in www.larochelle.today .
Are you working at Rosa or just developping their website?