The very (!) slight loss of Caster angle which does happen with any suspension lift after installing only a 2" spacer kit will not cause DW. Just about everyone with a suspension lift is running less than the factory specified 6-8 degrees of Caster angle and without DW... me included.
DW is caused by a lot of things... out of balance tires, loose trackbar mounting bolt, wallowed-out trackbar mounting bolt hole, bad bushings, loose shocks, loose trackbars, bad toe-in setting, etc. but not from the slight loss of Caster angle from merely installing a 2" budget boost.