As far as I'm aware, Lexus sells a few different lower control arms that have each different caster built into them.
Any reason you want to adjust caster?

 

The OEM LCAB come in 3 flavors. No offset, plus & minus 0.45° or something like that.

One can also buy offset ball joints and of course jockey with the engine cradle position if left to right balance is off. This can impact camber too.
Use a tape measure from symmetrical plug wells in body to each ball joint. You should get the same measurement. If not the whole engine cradle can be shifted a small amount. That said, the caster on these being 8+° a 0.5° difference typically goes unnoticed and has no impact on tire wear. Toe and camber impact tire wear. Camber and to a far lesser degree caster impact the ability to drive straight (hands free) on uncrowned highways.