Need Amount based Invoice Tolerance Rule for functional currency (GBP for us)

Hi CCC Members,

This question is regarding set-up 'Manage Invoice Tolerance' rules. Request you all to please go through the same and let us know if any workaround.

1. Existing Set-up -
   1. Quantity Based - 5% Ordered %, 5% Received %, 500 Total Amount, 5% price %
   2. Amount Based -  5% Ordered %, 5% Received %, 500 Total Amount
2. Current Oracle Functionality
   1. We referred Oracle doc and our understand that 500 amount rule is being checked by system only for foreign currency invoices (i.e. Non-GBP Invoices) and not for functional currency invoices (GBP).
3. Business Ask / Expected functionality
   1. We want to achieve tolerance rule of 500 for our GBP currency as well

Thanks in Advance!