Hello! Thank you for the feedback!
Yeah, the traffic is updated every second and can contain thousands of new positions. That is going to impact performance - to varying degrees depending on the hardware of course!
Also see this relevant topic: iPad battery drain
Which version of the app are you running? Make sure that you are on the hotfix 8.37.1 for the best possible results at the moment. We’ll always to optimize things as best we can, but this feature can be quite the challenge when there is a lot of people flying on the network!
See the Scratchpads topic in the wishlist! If you have not already voted for it, feel free to do so!
Kind Regards,
Malte