I’m gonna revert back to my old iPad mini 2, which is still running iOS 11.4.1 and SD 3.10.1 and running much smoother the my iPad mini 4 on iOS 12 (was unable to to restore 11.4.1 on my mini 4). I dare not update the mini 2 now.
What I’m noticing on latest version iOS 12 / SD 3.10.4 (mini 4), is performance reduces with usage over time (memory leak?).
On the mini 4, I can recreate it every time, by first killing the app, and then creating a route with one or two waypoints. I then go to Route - Start Again in the menu and then create the same route again. And then repeat over and over, create a route and start over. Each time, lag will increase. And this is just planning mode.
Theres no lag on iOS 11.4.1 / SD 3.10.1.
(Note, both devices are 4G capable, and I'm not running any 3rd party hardware).