The Ducati forks with top-out springs that I have encountered have pretty soft top-outs, so If I want to measure sag from fully and surely extended forks I do so by screwing the pre-load all the way in. As you say, that will completely squash the top-outs.
The aggro with non-parallell front axle bores .... extremely annoying. Would probably not be half as annoying, if only one had 3 hands ....
I have managed to slightly improve oval front axles by mounting them 90° (no wheel ...) and give them a good tightening. I think part reason they get oval is that they always sit in the same position on the Showas with fork-bottom adjuster. I did not measure anything, but I think it got sligtly better ....
Ducati axles are a bit too thin honestly I'd not mind hauling around another mm of thickness for much improved ruggedness.
Ducati's not great but it's heaps better than many other bikes where I need to use all 5 of my hands.
Very annoying as that means someone has to hold my beverage.
I've done dozens of Duc axles that way.
Check 'em for burrs first, and eyeball em to look for bends.
Then pinch on the 25mm diameter 90 degrees out they can be rounded up so they'll slide through the bearings.
Then do the fat end, confirm it'll slide through all.
The pinch bolts are easy to overtighten.
I've often thought that setup could do with some thin-shank bolts or M6's or something for some springiness.
Not much benefit being stronger than the axle it just crushes it.
I unwittingly dolled up a set of SS forks (I think) with black ano and SKF seals and nice valves for my S4 then realized they're short travel and they're pretty sucky.
I've got the springs and sag set good so it sits right and won't bottom.
But it's just stiff so it rides crappy.
I forget what the forks on my 750 had, it was a lot.
The SBK cartridges and Monster legs squeezed the last mm out of it, I had to check carefully that I wasn't going to use the damper rod as a bottoming stopper.
I'll fit those to the S4 see if it'll calm it down a little.