Turn off update in operating concern currency in a prod system

Hi

My client is upgrading from ECC 5 to 6.0

In COPA, both the currency types 10 and B0 are active... Apart from that the Op concern/Prof Ctr currency is also active

However, the operating concern currency is same as company code currency i.e. INR...

Thats why I was planning to have only currency type 10 and turn off all others like B0....

Was wondering what impact this will have on the system like impact on Open sales orders or on other things??

Regards

Ajay