Hiya there Rev,
Sorry mate, cant help you there :-?.... I tried as many roast variations as you have by the sounds of things, and in the end I tossed em all in the bin. I think they are a particularly hard bean and perhaps just do not lend themselves to popper roasting. I dont know really.....
Maybe someone with a Genecafe or a Hottop may be able to let us know how they went,