This is great feedback, and it gets at the hardest problem I faced making the game -- "How can I add gameplay depth and strategy to a dice roll?"
I really agree that the upgrades are lacking, and the 'weigh the dice' upgrade is really overpowered, while the 'add a dice' upgrade is way too expensive. The existing upgrades will need to be balanced for the post-jam version, but I'm at a loss for new upgrades at the moment. I think it's important to require the player to roll exactly 6 -> 5 -> 4 -> 3 -> 2 -> 1, so I'm against upgrades which would allow wrong rolls or count inconclusive rolls.
One upgrade that got cut was a physics simulation speed upgrade, where you can just make everything run faster overall. I like that and I think I'll bring it back, but it doesn't offer any strategy beyond the question of the upgrade cost vs. the expected value of faster rolling.
Anyway, I don't mean to ask you to design my game for me, but I really appreciate your thoughtful feedback! Thank you for really engaging with it. The constructive criticism is by far my favorite part of the game jam. Thank you for the nice comment!