Because the attack portion will overshoot even the highest setting of the sustain control (the maximum possible), it doesn't follow the classic description of an ADS or ADSR where the attack should never exceed the maximum chosen sustain level.
That means when sent to a VCA, there will be a short spike of volume that's louder than the maximum sustain level.
If the sustain level was to, say, "go to 11", this effect would probably not be noticeable.
In the VCF env, resistor R13 is normally 4.7Kohms.
But it should really be closer to about 3.7Kohms.
The same resistor in the VCA env section would be R47, but I've never had the desire to swap it with any other value for fear of removing this "punch."