On a related point, I went to get geo done recently, having re-done the whole front end but left the rear largely untouched.
Going in, the geometry was OK-ish at the rear in the static positions. I don’t recall the figures but in simple terms nothing was far from green and visually it looked very similar.
I asked the guy to see if he could improve. He loosened everything off and tried to adjust but said there was so much play in the bushes, the wheels weren’t moving even on maximum adjustment. Rear arms was definitely part of the adjustment. I asked him to lock down and he was good enough not to charge.
Having driven for a week I can see that the current static position is very obviously much worse than before, with the position of the rear wheels clearly different to each other. Not his fault, I think that is just a risk with worn bushes.
To solve I am replacing the lot. Really looking forward to it, the front end was transformed when I refreshed that.