Support burden is more than a yes/no question
Almost any orientation choice for a moderately complex part involves some support material somewhere; the real question is whether the total burden, how many separate regions need it, how large they are, and how severe the overhangs are, exceeds what you are willing to accept in cleanup time and surface risk. This tool builds a relative estimate from those factors rather than a binary "needs supports" answer, and checks it directly against your own stated tolerance.
How the estimate works
Each unsupported region adds to the estimate, weighted by overhang severity, since a mild overhang and a severe one are not equally costly to support. The largest single unsupported area contributes as well, since one very large support field is often more work to clean up than several small ones. The combined estimate lands in a low, moderate, or high band, and is compared directly against the support tolerance you stated to say whether this design is within your own bar or should be reworked.
Worked example
Two unsupported regions at moderate severity, largest area about 8 cm2, low tolerance: the estimate lands in the moderate band, which exceeds a stated low tolerance, so the tool recommends reducing support burden, most effectively by targeting the single largest unsupported region first rather than trying to eliminate every region at once.
A common mistake
A frequent error is estimating support burden from the model's appearance in a 3D viewer rather than actually slicing it and looking at the generated support structure. A shape that looks like it needs modest support can generate far more material than expected once the slicer's actual algorithm runs; treat this planning estimate as a starting point, then confirm against a real slice before finalizing.
Limitations
This estimates relative support burden from the regions and severity you describe; it is never an exact slicer material or time estimate, since actual support generation depends heavily on your specific slicer, its settings, and the support profile you use.