I devoted some time to Differential Synchronization in my article on CRDTs, if you're interested: http://archagon.net/blog/2018/03/24/data-laced-with-history/...
My sense is that it's not a particularly flexible approach, and falters under adverse network conditions, even though it feels very tempting.
[1] https://www.youtube.com/watch?v=S2Hp_1jqpY8