If this is implemented, then also please ask the player if (s)he wants to interrupt the sacrificing every time the "god's opinion" changes (ie. goes from "pleased" to "very pleased" etc.). Also, propose interruption if god seems displeased about a particular offer. Finally, document somewhere exactly in which order the items are then sacrificed (from bottom to top like in extended drop, probably).

Also interrupt if a hostile or potentially hostile monster wanders into LoS (in which case you need to get off that altar in a hurry!).

An extra command for this would indeed be nice.