Impact of sending 8 char BIC with XXX vs full 11 char BIC on SEPA Payment to Bank

In process of a global R12 EBS implementation.  In Europe, all payments will be made using the SEPA payment format.  Currently our bank branches are all populated with each unique BIC value of 11 characters however, several are 8 characters with the last 3 populated with XXX.

Does anyone know if there is any risk in having these last 3 characters (branch id) as XXX's?  To me, it seems as long as we have the correct IBAN, the first 8 characters should be sufficient to get the payment to the right bank in the right country.  What is the purpose of these last 3 characters?  To simplify our bank branch structure, can we just set up each branch with the only the unique 8 digit BIC values even if we know the full 11?  Will we encounter any issue with processing the payment without the last 3 charcters?