Improve performance of Forecasting Query

looking through Sentry One from the latest EOM a Forecast query stood out to me. This one is our highest by CPU but the runcount isnt terribly high and the average looks to have room for improvement. It amassed about 4 hours of run time from just over 1000 executions.

original query:
exec sp_executesql N'
DECLARE @IDList VARCHAR(MAX)
SELECT @IDList = COALESCE(@IDList +'','', '''') + CONVERT(varchar(20),ForecastId)
FROM ( SELECT ForecastId, ROW_NUMBER() OVER (PARTITION BY EntityId, BusinessDay ORDER BY GenerationDate DESC) RowNumber
FROM Forecasting.Forecast WITH(NOLOCK)
WHERE EntityId = @p0 AND BusinessDay >= CONVERT(date, @p1) AND BusinessDay <= CONVERT(date, @p2) ) f
WHERE RowNumber = 1 DECLARE @Query NVARCHAR(MAX) = N''
SELECT i.InventoryItemId, CAST(CASE WHEN i.ServiceType IN ('' + @p3 + '') THEN 1 ELSE 0 END AS bit) AS Excluded,
Sum(i.RawTransactionCount) AS RawTransactionCount,
Sum(i.SystemTransactionCount) AS SystemTransactionCount,
Sum(i.ManagerTransactionCount) AS ManagerTransactionCount,
Sum(i.LastYearTransactionCount) AS LastYearTransactionCount
FROM Forecasting.InventoryItemMetricDetail i WITH(NOLOCK)
WHERE i.ForecastId IN ('' + @IDList + '') AND i.IntervalStart >= @p0 AND i.IntervalStart <= @p1
GROUP BY i.InventoryItemId, CASE WHEN i.ServiceType IN ('' + @p3 + '') THEN 1 ELSE 0 END''
EXEC sp_executesql @Query,N''@p0 datetime,@p1 datetime'',@p0=@p1,@p1=@p2',N'@p0 bigint,@p1 datetime,@p2 datetime,@p3 nvarchar(4000)'
,@p0=192,@p1='2020-04-30 15:15:00',@p2='2020-05-08 08:30:00',@p3=N'1,2'

Schalk suggested we remove the in clause and replace with a temp table as below:

CREATE TABLE #tmpForecast(ForecastID BIGINT)
INSERT INTO #tmpForecast (ForecastID)
SELECT ForecastID
FROM (
SELECT ForecastID, ROW_NUMBER() OVER (PARTITION BY EntityID, BusinessDay ORDER BY GenerationDate DESC) RowNumber
FROM Forecasting.Forecast WITH (NOLOCK)
WHERE EntityID = 192
AND BusinessDay BETWEEN '2020-04-30 15:15:00' AND '2020-05-08 08:30:00') f
WHERE RowNumber = 1

SELECT i.InventoryItemID, CAST(CASE WHEN i.ServiceType IN (1, 2) THEN 1 ELSE 0 END AS BIT) AS Excluded,
SUM(i.RawTransactionCount) AS RawTransactionCount,
SUM(i.SystemTransactionCount) AS SystemTransactionCount,
SUM(i.ManagerTransactionCount) AS ManagerTransactionCount,
SUM(i.LastYearTransactionCount) AS LastYearTransactionCount
FROM Forecasting.InventoryItemMetricDetail i WITH (NOLOCK)
INNER JOIN #tmpForecast f ON i.ForecastId = f.ForecastID
--WHERE IN (6001224,6005391,6009586,6013947,6018380,6022699,6027063,6031384,6035708)
AND i.IntervalStart BETWEEN '2020-04-30 15:15:00' AND '2020-05-08 08:30:00'
GROUP BY i.InventoryItemID, CASE WHEN i.ServiceType IN (1, 2) THEN 1 ELSE 0 END