There was a wake encounter at DBX, A320 on final to 30L, hit a A380 wake from 30R at about 500 feet, rolled 40 degrees left, then 40 degrees right, ended up landing on 30R.
There are some studies now of the FDR data, using an equation equating to the sudden change in G force (how ever small). There are far more wake encounters that previously known. Also, most drivers dont take the time to report an encounter.
Using this data, there is are studies to determine acceptable levels of wake encounter.
It is not only the A380 to worry about. One of the deadliest ones I have measured was from a B787. The same high velocity, but a larger core, and long lasting. Many measurements of this ac in many conditions. Heaven help a 320/737 variant in trail to one of those.
Similar wings, although not as upswept, the A350, but only measured that ac once.
On the trail. The conditions that cause a trail do have significant effect on the wake. You will notice on many of the videos, the rollup does not occur very much below the ac, and does not appear to drop very much relative to the ac position. You can actually watch the wake slow to a stop not too far behind the ac.One has to believe that the conditions have to slow the wake down quite a bit.