Anyone with experience of half steps in loft ladders

[Lillis Ced]

We're going to build a loft ladder and are considering if half-steps are easier to walk on than regular steps. The tread depth will be 20 cm. Does anyone have experience with what is most comfortable? I figure everyone will back down regardless of the steps.

 

[Hep]

Even stairs that are meant to be descended backwards (e.g., on boats) have a normal step height, as do extra steep stairs. I can't see any situation where half-height would be better.