Sorry I don’t have an answer for you yet, but I am having this as well, doing a car racing game, the faster the car goes the worse the problem gets… the jittering is really frustrating! I also want to be able to use a full 360 camera, and have it “snap” back to being behind the car after a short delay when there is no input from the user.
Because of the jittering and custom functionality I want, I’m trying to work out a way of adding the camera lag without turning it on in the details panel, instead creating a custom solution in blueprint. It is still a WIP but I will make sure to let you know when I get it functioning, but it is a lot of trial and error and the moment… 
BTW unrealguy: I like the look of your game so far! Looks really cool