AME Invoice Approvals - How to use USD for approval levels for Mexico Peso Invoices

We have invoices entered for several countries, one currency in each Ledger.  We want to use AME for approvals and created rules to define approval levels based on USD.  If an invoice is entered in Mexico in Pesos (i.e. 250,000) we need this to go for approval at the USD equivalent (approx. 20,000).  We do not use transaction level conversions, but only Translate ledger balances to USD at a Period end rate.

I loaded daily corporate rates to try to force the Supplier Invoice Amount to convert to USD for approvals, but this is not working.  The invoices show up for approval at 250,000.