Hi Matt, there is not currently any way to turn off double sided shading.

In the future I do want to add a tool that would display the back side of a surface in some different color so that you could visually identify the direction and click on things to flip them. I'm not sure exactly when that will happen, maybe sometime in v3 though.

In the meantime the primary tool for this is actually Join - instead of having a whole lot of individual open surfaces you are best off having those surfaces joined together where they touch to ideally form closed solids.

If you have a closed joined solid, the mesh produced from that will automatically be aligned to have surface normals going to the outside of the solid.

Also even if you can't easily get the whole thing closed, it is still good to join together as many things as possible because a joined piece will have a consistent normal direction throughout it, so that makes for larger chunks of things that can be flipped at once.

- Michael