Great podcast as always! Thanks for continuing to put in all this work.
I learned something today! I always thought Shaman's Trance was the same as this card. Ultimately I think that cards that depend on your opponent's deck are too inconsistent for regular play.
The one scenario I missed in your analysis was against storm combo, where you can make mana from their graveyard much more easy and have more of an opportunity to chain these meaningfully. Then again, to get in such a situation probably means you win anyway.
I love that this card exists because it will create a few fun stories. Don't think it eill become a staple.