Front Upper Control Arms...

MaysEffect

That is equally vague. 32-38psi covers a huge variety of load ranges of about 300ibs per axle. 2 degrees of camber variation is also a huge margin for both steering geometry and tire contact. Changing the caster by that amount (4 degrees to 6 degrees) would possibly change your camber at full lock by 1-4 degrees.

This also doesn't take into account the wide variety of suspension setups these tire companies are advertising to. Cars without sway bars, cars with solid rear axles, cars with McPherson struts.

None of this is a problem for the Z. So additional caster AND camber is not a necessary change, its the reason nissan knocked the Z34 down to -+5 degrees of caster. If you want more response out of the tires, properly match the SR for the given wheel/tire you are trying to use. Not an easy thing to do when dealing with clearance and fitment issues (brakes or fenders). So yes, this is the ultimate compromise. Adding caster and camber ruins your instantaneous roll center. Something that will severely compromise how the suspension balance SHOULD be setup.