How to adjust inventory valuation with big amount 4M THB

We 're using cost profile as below

Then I want to adjust the inventory valuation when I realize that because of our operation's mistake, 1 miscellaneous issue transaction was costed wrong and lost 4 M THB from inventory valuation . I tended to use miscellaneous receipt and miscellaneous issue with unit cost and qty defined as below to adjust total amount: 4,196,087 THB.
My assumption is, because our new misc receipt's cost will become 1 cost layer in the future so we use the same cost as last layer cost exists in system to not make the cost layer value fluctuate. Then for new issue transaction, we define unit cost as 1 THB only.