I know that. You're not getting what I'm saying. I'm not talking about misaligning the brackets. That'd be stupid. I'm talking about moving them and keeping them on the same plane. Easy peasy compared to all the other stuff talked about here.
you said "I would relocate the front A arm brackets on each side out a little and the rear brackets on each side in a little" you would be better just to move them both rearwards on the chassis.
get two pencils and align them end to end, then roll one forward or rearward slightly, that's what the adjusters do to the bolts in the chassis. the offset bushes were just meant to alter camber and not to be misaligned to gain caster, but that is what they get used for. (i know you know this)
so with anything other than the bolts (pencils) being in alignment the rubber bushes will have to have an angle in them for the arm to move the ball joint more rearward. Fine if they are soft rubber but not so fine with a harder material.
and i actually beg to differ that it'll be easy just to move the position of the top arm mounts.