To your generalization. No.
In general, as development is increased the curve gets steeper.
It can be said that each emulsion/developer/technique combo creates a unique set of curves.
It can be said that some films will shoulder off as you have shown, but its not a general truth. For example, TXP reaches 2.8ish with almost no bend and gets well over 3 with just a little, the shoulder is still really steep though.
DR5 claims a D-max of about 3.3 for HP-5 chromes.
So where do we start bumping D-max for a given film? Where do we start shouldering? I don't know.