It’s hard to envisage what’s really going on dynamically with sliding stubs. I appreciate the view of rising rate for the initial half inch, but this must be viewed in the context of the main spring rate. Without actual data I can only speculate, but the effect of the rebound spring as it reaches full extension from half an inch compression isn’t straight line – it will reduce rapidly to zero. Equally the main spring on compression will rise rapidly from zero. Given that the main spring will be significantly harder to compress, then I’m unconvinced that the outcome of a shorter rebound spring will have much of an effect. Leaving ‘slackness’ between the stub and the rebound spring means that the initial downward movement of the stub is without resistance followed by ‘sudden’ resistance when it engages with the spring. I think that when cornering, this is not ideal for the inside wheel. This is just my hypothesis!
It would be interesting to experiment with spacers on the bottom plate to put this to the test, but that would be very time consuming. I have no problem with front end bobbing on 4 clicks and 25psi.