Rubicon 2 dr front lower arm extension

Lack of steering stability while straight running in Rubicon obliged my son replace front lower arm into 1 cm longer one in order to increase caster action. Now he is in test running, but remember here not only caster angle but also camber and toe-in values will be changed at the same time together if only lower arm length is extended. Let's see what will happen, though I'm afraid of getting himself into deep darkness, because he is not an experienced engineer to belong with some researching and developing division of the constructor. As for my opinion, he should not be suffered from product imperfections, he should enjoy his own life by utilizing Rubicon instead. I hope his effort will not become in vain.