Down at the bottom of the menu there's an altitude scale slider. It defaults to 1.2, changing it to 1.0 makes the trails look better.
It's amusing that changing the altitude scale doesn't reset the "trails" -- when I dragged it around quickly (on mobile) it left vertical streaks behind all the in-flight planes
I’ll fix that.
Fixed
Some comments: - Is the Up axis correctly scaled? The ascent rate of planes taking off seems very steep - Planes landing seems to get "stuck" at the beginning of a lane at about 600 feet (tracking/radar cutoff?), maybe a fix the that slightly adjusts it to ground in a landed state if a plane "stops" or disappears from the data tracking.