Billing in Multiple currencies

We are in 11.5.10.2 and use Oracle projects suite. Our's is a global company and we currently bill customers in USD and EURO currency. As we are growing across many geographic regions, we would like to start billing customers in many more currencies. However based on the amount of work that our accounting team does in terms to manage billing in mutliple currencies within one operating unit, we are hesitant to use it for other currencies.

Is there a way that we can bill customers in various currencies without having to create multiple rate schedules for each and every single org. We have 20-30 orgs and maintaing 300 different rate schedules ( 10 currencies * 3o orgs) will be cumbersome.