I really enjoy working with an iPad running Lemur as a way of controlling my MIDI-data into Logic. There is in my opinion no faster way regardless if you just want to record some automation data or if you're designing new sounds.
I also really like Logics built-in synths. They are perfect for adding an extra dimension where there is a need. They are always available and they take up modest resources. They are however not the easiest plugins to use on a 30-inch screen.
Solution: build some templates for Lemur on iPad! Download the free one and try it out for yourself.
It just works!
There is no need to MIDI-learn anything, it is designed to work with Logic Pros internal fader-data. All you need to do is add a transformer to change the type of data from Controller to Fader.
So what does this template do then?
It's a template for Lemur. With Lemur you get to control your DAW/MIDI from an iPad. This template does not contain Lemur itself, only a controlling template for Logics E-synths (EFM1, ES E, ES M, ES P and the ES1).