It could be done pretty easily I'm sure. But how much offset would you need? Every truck is likely somewhat different in this regard (as I think we've already determined). And the angle of correction needed would change based on amount of lift, amount of C-bushing offset, radius arm drop brackets or not, trackbar drop bracket or not, aftermarket radius arms or not, and probably other factors as well.
Then there are those that change back to lower offset c-bushings and rotate their steering yokes and knuckles to get batter caster. Which changes the needed angle of the trackbar mount again. Add FW axle swaps to the list, and that adds more possible angles.
With pretty much each of those being an option that can be varied by the owner in whatever combination they're shooting for, it would be a trial-and-error kind of thing for the end-user to align it right.
Still, an offset bushing with a degree scale molded into the flange edge for reference might allow for easy comparisons of angles during initial setup. A molded-in maximum angle could be determined/guessed at, then the user could rotate the bushings in the eye until the bar lined up with the mount.
Not a bad idea, but not sure if it's worth the trouble and expense either. Might be. Depends on how many people think it would be a good idea and buy one?
And remember, this is just for the "neutral" ride height. Any suspension movement at all changes the angle, and therefor the pressure on the bushings and bars.
Paul