I was just crushing some Beryl and it filled up the Red slot in my first element pouch. However, instead of putting the rest in my empty overflow pouch, it just discarded a whole bunch of red elements.
"You crushed 300 Chunks of Beryl (+360 xp, 0 energy). 500 Red Elements were created, but destroyed, because you couldn't carry them. You got 5500 Red Elements, 600 Green Elements, and 1200 Blue Elements."
I'm sure this has worked correctly in previous tests...