Validation Is Not Printability
Why a validated mesh is not proof the part will print, fit, or be strong enough.
What validation covers
A successful check means the mesh passed the engine's geometric tests, including a complete scan for intersecting triangle pairs, and, for repairs, that the exact bytes to be saved were re-validated.
What it does not cover
Passing is not evidence of printability, fit, wall thickness, strength, or the intent of the source design. The engine does not certify the containment or orientation of multiple shells. A mesh can be valid and still be a bad print.
Warning
Always inspect the result in your slicer or CAD tool before relying on it for a print or a fit-critical part.
Units and placement
STL files do not state their units, so the app shows dimensions in "STL coordinate units" and never labels them as millimeters. Negative Z is reported as a placement warning only; the app does not move the model onto a print bed.