How to enable approval rules at distribution amount level for FX transaction?

Summary:

For any FX transaction, in any currency, Oracle must first convert the value into NZD based on the current system rate, and then assign the appropriate rules. Example - $40k USD equates to more than $50k NZD, so the appropriate Tier 2 rule for $50K - $250k should apply.

In Order to accommodate the requirement, we hardcoded the currency NZD with Total distribution Amount in the existing rules and created new approval rules for the invoices which are not entered in NZD with Total distribution base amount and hardcoded the currency in those approval rules as well.

But Client is saying that this solution is not feasible, and they need a simpler solution. They do not want their approval rules to be doubled.