You can use your global account IBANs to receive funds from anyone. There are no specific limits.
Some typical uses cases include:
Attaching these details to invoices to receive payments locally in the customer's currency
Multi-national companies that need a local account
Receive funds from payments processors
Freelancers who have clients globally and want their customers to pay locally in their country and currency
After you've received payments into this account you can use it to fund exchanges directly.