Setting holdingsType=-1 in the Diagram definition takes care of these types of demotions automatically.
Ah, good. Nothing to worry about, then.
Also, you say promotion is mandatory upon reaching the last row. Does this promotion rule apply to all pieces or only to Pawns? If the former, does it also apply upon leaving the last row after a drop?
I should clarify that in the text. It only applies to Pawns, because an unpromoted Pawn on the last row is trapped.
Ah, good. Nothing to worry about, then.
I should clarify that in the text. It only applies to Pawns, because an unpromoted Pawn on the last row is trapped.