We agree, the bass note (or chord inversion as it is also sometimes called) is very useful information. After some investigation, it appears this would be a very large undertaking. We have however been working on this and we hope to implement this soon. Stay tuned!Bill commented
it appears that in some song transcriptions the chosen chords are actually driven by the bass note. For instance The Plank by Devil Makes 3 has listed progressions that are in no way factual after the first 8 or so bars.