Stiff front end looking at aftermarket solutions

To get as much Up Travel i have turned mine down until its almost at the bump stop.
Wait what? If that is true; then of course by your push-down test, it will be stiff, as the suspension has almost no where to go, and the T-bars have very little preload on them..... so basically the bumpstops are bouncing it back up, and then the chassis lands back on the stops halting downward progress; and the noise we hear is the bumpstops complaining about it.

In this instance,I can't see your push-down test being valid.