Caster is not a wear angle. So more or less caster will not effect ET, it will only make the car stable and help the steering wheel return to center. Uneven cross caster will cause a pull and cause steering input, which will cause scrub to occur.
Caster needs to be 0 at the ride height the car is going down track. Cross camber needs to be 0, or again the car will pull and the steering input will cause scrub.
The above will usually cause a pull to the right on a regular road due to road crown. You'll also see what looks like too much negative camber at static ride height.
Unless your current alignment is so outta wack, there should really be little ET gain.
And don't forget Toe, but you didn't ask about that.
Caster needs to be 0 at the ride height the car is going down track. Cross camber needs to be 0, or again the car will pull and the steering input will cause scrub.
The above will usually cause a pull to the right on a regular road due to road crown. You'll also see what looks like too much negative camber at static ride height.
Unless your current alignment is so outta wack, there should really be little ET gain.
And don't forget Toe, but you didn't ask about that.