Would DD Pro also get to level 3 or just DD Pro 2?
I don't know, but I think the principle is like this:
L2 requires a less powerful system than L3. To compensate for that weakness, it relies on humans to monitor driving conditions at all times and take over whenever necessary.
L3 requires a less powerful system than L4. To compensate for that weakness, it relies on strict conditions, such as Mercedes L3:
1) Geofenced in pre-mapped freeways
2) No construction zones allowed.
3) Daytime in good weather, not even rain, fog, snow... allowed. It has a wetness sensor that shuts down L3 when it detects wetness.
4) Slow speed (40mph in the USA)...
Thus, if DD Pro is weaker than DD Pro 2, it can still do L3 if it can add stricter conditions, such as a slower speed or requiring a leading car in front...
All L3 systems are not equal. BMW Personal Pilot L3 works at night, while Mercedes doesn't.
L3 means that when all required conditions are met, the system can drive on its own without humans. Still, there are times when the conditions are not met, such as when a dry day becomes a rainy one: The Mercedes L3 would then detect wetness and it would alert the human and hand the driving task over to a human.
I think the challenge for L3 is it might be too restrictive to be practical for a driver who wants its L3 to drive the legal speed of 85mph on State Highway 130 but it can only do 40mph!
However, even with strict restrictions, I think it's a welcome improvement over L2.