I boarded a flight at CDG 2F yesterday, which has the two lanes. Skypriority sign was available, and BP's were checked if indeed everybody in the SP lane had the proper permissions.

At boarding time both lines opened simultaneously though. As this was a flight to AMS it had at least 50% elites on board. This resulted in a huge SkyPriority line, and a medium 'normal' line. Since both opened at the same time, most people in the normal line boarded first

So it would have been nice if they kept the normal line waiting until the SkyPriority line was finished boarding. On the other hand I guess it is good that now at least they check the BP for the SkyPriority logo, in the past they would not check at all.