Hey big guy were those photo's Vac purged or heat? I assume Vac because it looks so dry. I've gotten stable wax like but no so dry and breakable as that. I know I've overheated my current batch, bummer it was the best so far. I'm definitely getting better. It's all practice.
You can also add ball valves to the top and bottom for timed soaks.One on top even just to stop back flow when changing out cans.The one I listed will fit about 112 to 180 grams of material.
One can of butane per ounce of material is the suggested amount.Blast tane through the column of material until the liquid tane coning out the bottom of the extraction tube turns clear...no more butane needed.
I never use grinded or cut up material as you end up extracting even more fats,waxes,and lipids,and in some cases chlorophyll.
I like to take freshly dried buds and break them down off the stems till they are all perfect bong toke/bowl pack sized buds.