def METHOD_NAME(
    rr: list[ResultDict],
    across_key: str,
    summarize_metadata: bool = True,
) -> tuple[list[ResultDict], list[ResultDict]]:
    groups = group_across(rr, across_key)
    expanded_groups = group_expand(groups)
    aggregated: list[ResultDict] = list()
    bypass: list[ResultDict] = list()
    for index, elements in expanded_groups.items():
        tags: dict[str, Any] = {
            across_key: [element.across_value for element in elements]
        }
        tags |= index
        u = merge_data(elements)
        u["tags"] |= tags
        if len(elements) > 1:
            aggregated.append(u)
        else:
            bypass.append(u)
    return aggregated, bypass