With some icons of the Akar-icons collection (see "Behance Fill.svg") the Dual Mode conversion fails. The tool should not only ignore "non-shape tags" (defs in this case) but also everything whats inside defs even if the content matches a shape.
Behance.svg:
the conversion result is completely white/black because the rect fills all the space.
EDIT: You may have noticed that you can't generally ignore the content between "non-shape tags" because "path" is between "g"-tags.
I tried the new version with Akar-icons and created a dual mode iconset with the converted files and your Iconset Maker SVG.
All icons are looking fine now. Thank you for fixing that.