Dude it has nothing to do with pouring it early. It’s too thin. Make your paper smaller. Make it thick. My friends want it how yours is but I make it too thick. 200 gram slabs and they complain lmao.
I suggested that it was an early pour due to the size of the bubbles, suggesting copious quantities of LPG present.
We extract as cotton candy, which is arguably the other end of the scale and doesn't present the same issues. Everything is expanded into foam, but no bubbles fighting to escape from a sub melting point matrix.
I suggested low temperature because the bubbles didn't heal. At melting point that isn't an issue.
Thickening a slab, most certainly involves surface area versus volume, so good point as one of the pertinent details!