Google Analytics 4とbigqueryでUniversal Analyticsと同等の結果を出したい件

-- Universal Analyticsと同等のページ情報を取得するCTE
WITH page_info AS (
    SELECT
        user_pseudo_id
      , (SELECT value.int_value FROM unnest(event_params) WHERE event_name = 'page_view' AND key = 'ga_session_id') AS session_id
      , event_date
      , event_timestamp
        -- regionとcityが未設定もしくはNULLの場合、Universal Analyticsと合わせて'(not set)'を設定
      , IF(geo.region = '' OR geo.region IS NULL, '(not set)', geo.region) AS region
      , IF(geo.city = '' OR geo.city IS NULL, '(not set)', geo.city) AS city
        -- URLからスキームとホスト名を削除、UDFを利用しない
      , (SELECT REGEXP_REPLACE((SELECT SAFE_CONVERT_BYTES_TO_STRING(ARRAY_TO_STRING(ARRAY_AGG(IF(STARTS_WITH(y, '%'), FROM_HEX(SUBSTR(y, 2)), CAST(y AS BYTES)) ORDER BY i), b'')) FROM UNNEST(REGEXP_EXTRACT_ALL(value.string_value, r"%[0-9a-fA-F]{2}|[^%]+")) AS y WITH OFFSET AS i), r'https?://([^/]*)', '')  FROM unnest(event_params) WHERE event_name = 'page_view' AND key = 'page_location') AS page_path
      , (SELECT (SELECT SAFE_CONVERT_BYTES_TO_STRING(ARRAY_TO_STRING(ARRAY_AGG(IF(STARTS_WITH(y, '%'), FROM_HEX(SUBSTR(y, 2)), CAST(y AS BYTES)) ORDER BY i), b'')) FROM UNNEST(REGEXP_EXTRACT_ALL(value.string_value, r"%[0-9a-fA-F]{2}|[^%]+")) AS y WITH OFFSET AS i) FROM unnest(event_params) WHERE event_name = 'page_view' AND key = 'page_title') AS page_title
      , traffic_source.source AS source
      , traffic_source.medium AS medium
    FROM
        -- ★データセット配下の全テーブルをワイルドカード指定
        `my-project-***************-bigquery-test.analytics_**************.events_*`
      , date_range
    WHERE
        event_timestamp >= date_range.search_start_date
    AND
        event_timestamp < date_range.end_date
    AND
        event_name = 'page_view'
    AND
        geo.country = 'Japan'
),
                                                                                                          

-- セッション情報を取得するCTE
-- landing情報抽出、メインクエリ上ではlanding_timestampとevent_timestampが合致するレコードにセッションを加算する
WITH landing_info AS (
    SELECT
        si.user_pseudo_id
      , si.session_id
      , landing_timestamp
      , pi.page_path
    FROM
    (
        -- エントランスの判断のため、ユーザーID＆セッションID毎に最古のタイムスタンプを取得
        SELECT
            user_pseudo_id
          , session_id
          , MIN(event_timestamp) AS landing_timestamp
        FROM
            page_info
        GROUP BY
            user_pseudo_id
          , session_id
    ) si
    LEFT JOIN
        page_info pi
    ON
        si.user_pseudo_id = pi.user_pseudo_id
    AND
        si.session_id = pi.session_id
    AND
        si.landing_timestamp = pi.event_timestamp
),