Hey, i use a combination of tek's, mainly Lextek, The Handbook and Whatcha's, with hydrochloric, and phosphorus sometimes, i find with hydro there is less chance of failing the synthesis, and there tends to be less fat/oils on the surface of the boil, plus it is allot cheaper...
I have had acuminata(8 narrow leaf) growing for around 2.5 to 3 years, the older they get the better... It was the same for me at first, brown/yellow crumb, i figured that the crumb was plant matter/membrane being pulled with the solvent, a quick wash with shellite and back in the freezer(crystals formed, although slightly oily), plus the first extraction was with only 100g of leaf and i basified the cook without straining, the following extraction was allot better, i used around 1kg of leaves... acid cooked and strained X 4, reduced(1 liter), salted(rock salt), basified, pulled, re-salt(hydro), basified, pulled, bi-carb wash, in the fridge for a day, then in the freezer... around 4.5grams of fluffy white pure love

You must do a proper defat, i have thought about soaking the dry matter in turps, separating, drying and then the acid cook to see what happened, maybe there will be less oils/non polar impurities and a post defat may not be necessary, i'll give it a shot sometime... aromatic solvents would work best for this, rather then shellite i'm guessing, also, freeze the fresh leaves after harvesting, burst the cells, dry and freeze again, grind the dry matter before cooking, more fine the grind the better.
The Acuminata are slow growing, but you will see when they are around 1 to 1.5 years old, and in the ground, not potted, they really start to shine, with full sun, they wont be as flimsy and floppy if you know what i mean, and never use blood and bone, for some reason the acacia do not like it, none of the them, i lost a few.
With the Longifolia, i wasn't sure if i made the correct id, because there was more yield in the root bark, there was a huge storm in the area and several mature tree's were uprooted, it was like heaven, harvesting without a conscience, 4 kilos of root back, double that of trunk bark, from 1 tree! after more researching i was 100% sure that i had made the right id, phyllode structure, size, shape, length of flower, color, bark texture etc and yet it had never been documented that the root bark was considered to be active, well not what i could find, i never did an extraction on the phyllodes, i was to busy enjoying the bark..
a note for the root bark: the fresh inner bark is white/yellow/brownish, upon tasting/chewing there is a tingle, a dry flavor, the smell is dry, fruity and slightly pungent.
Testing the extract caught me by surprise, i sandwiched the goo, a big blob of it and sparked up, at first there was nothing and i thought, damn nothing, what a waste of time, 20/30 seconds later it dropped me, i was in fairy land gasping for air, sitting upright on a tall chair riding it like a electric bull, aahh man thank god i was alone, i was rocking all over the show, holding on for all... i had never had that physical effect before, with any other acacia or mimosa, definately a distinctive effect from longifolia, i recall when having a large dose the tension in the upper body/skull almost became uncomfortable, even painful at first, the feeling always subsided it was only ever brief, i gathered that there may have been residue sodium hydroxide, but there was no stinging/burning lips or tongue, and no caustic flavor, only the nice dmt flavor and smell, plus after another extraction, the same effect.
I thought i would mention this, since i found it interesting, i have noticed that grasshoppers tend to not eat much of the acuminata phyllodes only ever a nibble, they love mimosa, confusa, cauliflorous, florabunda, and won't touch viridis... i wonder why.