I am in no way an expert on the care and maintenance of Junglesop (Adam would be the expert in that category), but in my experience the seeds germinate faster than other species in Annonaceae, sending a very long and brittle (breakable) base root. I accidentally kicked a pot over and the root snapped and the seed died. Best bet would be a very long, but also not very wide pot with well draining soil and a warm environment.
Did read online somewhere that researchers have planted trees that went over two decades without producing fruit. The dream would be to start your own seedlings to a considerable size and somehow obtain scions of one of the better varieties and get your graft on.