Bleeding ABS control unit on A4 B5

[FrenchAudi]

I notice that some cars have a procedure, done after normal bleeding, where a scan tool is used to bleed the ABS control unit. I assume this is to remove air or contamination trapped in the unit's pump and valves system, which can not be removed by normal bleeding. Here is an example How to bleed brakes with a scan tool. No pumping necessary - YouTube

I would like to know whether this is possible on my car, which has a Bosch 5.0 system.

Is this procedure necessary only on certain cars, or on any car when a control unit is replaced or air has got into it?

Is some fluid always trapped in ABS control units when changing fluid, but is insignificant?

[Crasher]

The Bosch pumps don't have that feature.