On the other hand, it might be difficult to implement. The ratio of force to delay might not be a simple inverse proportion.

Hammer delay effect simulation in PW

I found it out, that this wasn't reflected in the MIDI stream out of the keyboard, so it had to be implemented in the sound engine.

Basically two acoustical phenomenons are there to be considered:
1. high velocity keystroke is producing faster (fast immediate) hammer impact, than with a pp playing on the same key (having to travel faster the same distance takes less time).

2. Hammer in the bass are longer, needing longer travel time.

This behavior should implemented as an optional one, also because of the possibility to implement this by MIDI gear. 

I didn't find such an option in Pianoteq, although PT would be an obviously great place for it.
Have I missed something? Otherwise I would like to add this to user's wish list.