Those are some good suggestions. I'm playing with spawn rates a little bit, but I'm thinking of having them do more or last longer rather than increasing the number, mostly to make finding them more joyful.
Maybe it makes sense for the dead-ends to be the only things that have potions so that it's exciting to find them. Or punch more holes in the dead-ends.
Don't know of a good way to do the countdown timer that isn't super distracting. Maybe some more audio queues and louder stretching noises.