> If I do address math on the pointer in order to find a payload, then isn’t the payload tied into exactly one next pointer, and thus exactly one list?

The container_of macro takes the type and member - so for a different member it can subtract a different offset.

Going more basic, you could imagine creating something like:

    struct Node {
        Node* next;
        Node* next_10th;
        Node* next_100th;
    };

The normal, 10ths, and 100ths lists are distinct collections, this is the basic idea. The macros just help generalise it and make it more usable.