Have you tried insect frass / castings ? We were researching what to do with the bio-product of our edible insect farm and discovered the super fertilising power of insect frass.
As well as being rich in micro-organisms and nutrients it contains Chitin. Recent studies have found that Chitin improves crop yields by tricking the plants' immune response to produce more natural toxins to fend off insects and produce more fruit and flowers.
I see it is sold ommercially in pellet form, but we have only ever used the fresh one from our farm.