Suppose I have a Commerce B2C solution for two or more stores in a corporation.

• Each store has its own product catalog.
• Each customer can create an account in each store. Each account has its own login user, which is linked in the CustomerContact.UserId property.
• An order in store A will be linked to the customer contact in store A. An order in store B will be linked to the customer contact in store B. And so on.

How would you guys solve the "get current customer" on the site?

It looks like the CustomerContext is limited and impossible to override or replace (it has no interface and is accessed from its singleton property).