I haven't a technical answer to your question, but it does raise an interesting theoretical point.

Guitar FX tend to be mainly, but not totally, independent of the dynamics of the played guitar. This isn't an absolute - I've noticed an increase in intensity from a reverb pedal, for example, when the guitar/amp volume is ramped up - but, in general the FX will act on the guitar signal independently of any playing dynamics.

So (to get to the point), if you change voltage paths so that the FX do respond to a single guitar dynamic - attack, in your example - then remember that other factors such as tempo, volume, etc., may or may not be factors as well.

Given the technical sophistication of pedal and rack equipment these days, I would have thought that a programmable, rather than a physical, approach to FX dynamics might be an easier path.

Just a thought.