Can we create 300 roles in VBCS and will it decrease performance

Summary:

We have an Customer Facing application and each customer has to see only his data in a BO. BO has Customer Name. To achieve this we have to create role for each customer and assign customer name in Role View Criteria. So we have to create 300 roles and will it  decrease performance of the application.

As VBCS has open Rest services , creating generic role and restricting it from UI will not work. From Developer Tools one can get the Rest Service URL and access it from SOAP UI/Postman tools etc.

We cannot remove Basic Auth in VBCS Settings as data to BO's is getting populated from other systems using OIC Integrations.