I am trying to design a project featuring MAX25431 buck-boost converter. 
After examining the datasheet I started the part selection for my application, but I have troubles understanding few details:

 - In the first image the inductor value is calculated from the max/min duty cycle in boost/buck modes respectively. In their equations the converter efficiency is used, and further down in the example it is selected as 95%. The question is how this value is chose and why it is just thrown like this without any explanation.
 - Second question is why LIR is chosen to be so high? According to what I read online it is supposed to be around 30%.
 - And the last question is why the 2nd example that they give on image 2 is really different from the 1st design example, and why only the Lbuck is calculated?

[![1st image][1]][1]
[![2nd image][2]][2]


  [1]: https://i.sstatic.net/RYHFq.png
  [2]: https://i.sstatic.net/dDJlg.png