A quick answer because I have to go --- Bokashi - EM fermentation -- produces heat. It can get almost hot on top of the bin when they are actively fermenting. I think the gasses they produce (like bubbling yeast/bread dough and fermenting pickles) would drive or combine with existing oxygen.
The bottom mesh/grid and riser is consistent with my Bokashi container. Are those small drilled holes to the outside in the lowest part of the container? That's the part I'm not sure of.
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