A few notes for possible future updates:
I think that the issue of creating the "placeholder" cards is when you are clicking through draw cards and your library hits zero before the discard pile gets shuffled back. They can get stuck in place weirdly and make it impossible to proceed.
On balancing, I think that the walkie-talkie, gold mine, and wrench strategies are too easy versus the various upgrading strategies. Especially, I'd like to see the anvil get a boost - I've tried to force it many times but have never been able to have all the pieces line up.