You still have promoZone=1 (and maxPromote=1 by default). This causes conflicting instructions to the Diagram: it must both promote the Pawn with the choice given in promoChoice when it reaches last rank, and you specify it to morph there. Promotion per zone/choice prevails in that case, so that the morph specifications for the last rank are ignored. Just set promoZone=0 and the morph would take effect.
You still have promoZone=1 (and maxPromote=1 by default). This causes conflicting instructions to the Diagram: it must both promote the Pawn with the choice given in promoChoice when it reaches last rank, and you specify it to morph there. Promotion per zone/choice prevails in that case, so that the morph specifications for the last rank are ignored. Just set promoZone=0 and the morph would take effect.