You shouldn't need a BMC with your wheel specs. and tire combination, assuming your 285 are 285/70R17 and you do not have wheel spacers. Try and get another alignment.

Everyone says to get all camber possible, etc......but realize CAMBER is also only done with the lower control arm. Something has to give if they cannot get both camber and caster. You may get the caster but have positive camber and the tires will be obviously angled out at the top and have very fast tire wear. Or more neutral camber and negative caster. With 2.5" lift you SHOULD be able to get both with factory UCA's. Noted... positive camber will push the wheel further back in the wheel well and tire closer to the body mount. Aftermarket UCA's can make this even worse.

I did not need a BMC with 285/70R17 Wildpeaks on FX Pro wheels with same specs as your six shooters. This is with 3" lift and Dobinson UCA's

What are y'all SPCs set at? Middle "D" setting (+2)?