Thin faces warning 3Dprint tools I am using an industrial grade 3d printer, it has a voxel acuracy of 23 micron.
Although i cannot show my model here, its about 1000 times larger then the default suzan, as i export it later to STL, and as blender isnt aware that the default stl scale for 3d printers is mm.  (the STL format itself has no size, but scaling it 1000 times works well)

Anyway with those large objects in reality just a few centimeters tall, i kinda get random warning of thin faces.

Is this normal, or should it reported as a bug ?.
There are two ways for you to handle this.

The first is through the length unit settings in the scene tab of the properties panel (bottom right in the image below). You can simply set the scene units to millimeters instead of meters (which is the default), and the 3D printing toolbox tests will update accordingly.

The other one is by changing the thickness threshold in the 3D printing toolbox thickness tests to whichever is the limit you're aiming for (which corresponds to your 3D printing tools and materials).