Odoo posts unrealized exchange rate adjustments at the end of a period using the closing rate, and then automatically reverses those entries on the first day of the new period. 

This avoids duplicating the impact in the following period - when another entry is generated. 

While this may appear to recalculate audited balances, it aligns with IAS 21 if the revaluation process is run again using the correct closing rate of the new period.

IAS 21 requires monetary balances to reflect the closing rate at each reporting date, and only to be settled at the rate on the settlement date. So, Odoo's mechanism is compliant as long as revaluation is performed at each closing, and exchange rates are correctly updated.