Everything on my Air 2 lags on iOS 11 that’s why I upgraded to IPad Pro but even that has stutters on iOS 11 hence I kept it on iOS 10 and it will stay that way till iOS 11 has zero stutters.Then you will complain that there is "swipe up" lag.
There is more of a swipe up lag on my Air 2, than there is home button lag on my 8 Plus.