Thanks for your feedbacks and Kevin, for your donation.

@Keet Your comments from someone who also spent a lot of time on designing staircases 3D models are really appreciated.

If we can just have the ability to remove only the handrails etc on either the stairs or landing plus with or without the string , it’ll be perfect.

I hesitated to use some different material names for each part of the handrails and balusters, but for U shaped staircases, it would make many materials with the risk of confusion for beginners. Maybe, I could add an option for a limited list or a full list of materials.

@sjb007 Thanks for the translations. As English style used in Sweet Home 3D is more American English than British English, do you think it would be the same in American English?

One small cosmetic detail is that the stringers are sloped at the turns in both this method, and the "U shaped with top/bottom landing" options when "Turn step count" is set to 1.

I agree this is a little odd, but it's for aesthetic reasons so the stringers look better connected and more continuous. Otherwise I could have added a pole like in the U shaped with landing staircase.

Do I detect a little "official business"? So I take it the French police are using SH3D in crime scene presentations or something like that? Cool!

Yes, the French police have used Sweet Home 3D to model crime and road scenes for a few years, and they agreed to contribute to some improvements and additional 3D models. See this article and their interview (in French).