There is a reason why tapers on crank spindles are long gone...except for the ghost of square taper aka Power Torque. Canvas the industry. Nuff said.
In the case of Campy square taper, the design was further hampered by small square surface area...high stress...and hence tendency for spindle bolts to fall out...lol. Shimano moved on as well...from Octalink to their current excellent straight spline with double pinch bolts. I own it on one of my bikes and it is superb...as good at UT, just different. Sad to see Campy unlearn the leason of Octalink...but fortunately they still offer UT on their higher end stuff.