We have correctly used your setting threshold guide to set our threshold. But when we set a custom threshold, no reading is achieved, and all the elements return empty values. When we tried it in your OMR template editor, it couldn’t read when we enter a threshold value less than 0.3. We suppose that by setting a threshold you mean, 0.1 => at least 10% of the selected area should be filled.
Find attached to this our sample template and image.