On reflection, I’m inclined to agree. IFRS doesn’t have a standardised sub-total for these items - actually, a proposal to show a subtotal “Net Finance Cost” in the Income Statement was rejected by IFRIC unless the individual line items are also shown.
https://www.iasplus.com/en/meeting-notes/ifrs-ic/not-added/2... However, the terms I have seen used (e.g. “Net Finance Cost” -Unilever; "Net financial income/(expense)" -Nestlé) do include items 16 and 18, according to the Notes to the Financial Statements.
Unilever states : “Net gain/(loss) on transactions for which hedge accounting is not applied
*On foreign exchange derivatives
*Exchange difference on underlying items”.
Nestle states : “These headings also include other income and expense such as exchange differences on net debt and results on related foreign currency and interest rate hedging instruments.”
While I don’t think it would be actually wrong to use “Net Finance Cost”, particularly as it would be a defined term (Sigma items 14-19), I do agree with you on the principle that “Localisation must never trump accuracy”.