I would agree that in the best of all worlds, you would input all of the data requested for the baseline. However, the app does give the option to skip the input for single arm, both lead and trail. I know that @OldandStiff has had some injuries and when he asked the question, I inferred, rightfully or wrongfully, that perhaps those injuries make it difficult for him to swing with only one of his arms. If that is true, the app might try to develop a program that would strengthen something that cannot be strengthened. I don’t know if that makes sense, but that is what I was getting at. I was trying to say that since the app gives you the option to skip that input, it must be effective without it.
Well, the good thing is if you do not agree with the App's order of training phases, they are only the App's recommendations. Skip and re-order the priorities where wanted.