Regarding the trick, you are the only one who noticed and I had no idea myself until I checked. I will fix it.
As for the bug, block of the upgrades works only for each 30 rerolls, for now. After the 30 rerolls, the upgrade returns to the pool.
I'm glad that you've picked up on the shop level up. Some of the players take the bait to spend gold on the choices instead of shop level up. I think I'll need to make an improvement to encourage players to actually level up.