Emmanuel, the problem with splitting a curved wall is that is doesn't retain it's form. When I split a half circle I get two half circles next to each other while I expected to still have the half circle but now in two parts. Is that one of the bugs you were referring to?

I didn't know the ctrl-key "trick" so I tried it. Using your described method I managed to create a circle wall starting with a 90° part and continuing with using the Ctrl key to add 90° parts until you have a full circle. That seems to work perfectly although you have to move the mouse to weird places to reach 90°, sometimes very far from the wall [:))] This might be considered another bug. The mouse move should work like when you curve an existing wall using the marker in the middle of the wall.

Drawing 90° parts seems to me a better method than what you described with splitting 180° walls. It works without copy-paste or splitting and the wall parts remain joined. It's definitely a better way then the copy-paste-coordinates system I described in my previous post.