Compute effective approach; sumx, summarize, sum - case of transactional sales data and exch. rates

I continued a bit on my own.

Current trial;

Sales Revenue = 
VAR ExchangeRate =  Calculate(
                        min('Exchange Rates'[Rate]),
                        filter('Exchange Rates', 
                        'Exchange Rates'[From Currency]=MIN('Sales Revenue and Cost'[Currency]) && 
                        'Exchange Rates'[Date]<=MAX('Sales Revenue and Cost'[Date]) &&
                        'Exchange Rates'[To Currency]=SELECTEDVALUE('Reporting Currency'[Currency])
                        )   
                    )

RETURN

SUMX(
    SUMMARIZE('Sales Revenue and Cost','Sales Revenue and Cost'[Currency]),
    [Sales Revenue LCY] * ExchangeRate
)

With [Sales Revenue LCY] being;

Sales Revenue LCY = SUM('Sales Revenue and Cost'[Line Amount])

It seems to perform better compute and memorize-wise, and a visual with Year-Month calculates correct Reporting Currency Amount but totals the columns incorrectly with total sum of LCY times "Last Exchange Rate"...

And I still have my doubts if this is best practice at all 😞