how they flash is irrelevant if they aren't E marked, as the coding to the car could be changed to make them flash however the manufacturer or third party wants. Secondary to that it may fail an Mot on the number of flashes per second, but I don't know. Basically if it isn't E marked, it isn't technically legal for U.K. Road use.
Aren't they enabled through a wiring harness connector using the original lamps? If so, the indicators will be E marked as they are original.
The pace indicators, as per the video, are standard UK back lights that are coded via VCDS or OBD11. The semi dynamic indicators are again standard UK back lights with a small loom inserted - not sure that has to be E marked? For full dynamic back lights the 7.5 back lights have to be retrofitted and these possibly require coding and maybe an additional audi module - please correct me if I'm wrong as I'm interested in doing this?