Whether export payments can be received in KRW from a third party instead of the transaction partner

Our company exports to an overseas entity (buyer) within Korea. We conduct transactions of a certain scale every month via foreign currency transfers under DAP and T/T terms. Starting this month, while maintaining our previous export transaction methods, we have decided to receive the payment portion in KRW from a domestic corporation that is an affiliate of our overseas buyer (the two companies are legally separate entities and do not have a parent-subsidiary relationship). In this case, since our company is not initiating a third-party payment through the remittance of foreign currency abroad, I would like to inquire whether we can receive the accounts receivable into our KRW account from said domestic corporation—much like receiving a standard payment—provided we have an agreement or contract signed by all three companies. Or, are separate procedures or supporting documents required from other institutions? (We are keeping potential foreign exchange gains/losses in mind). Additionally, from the perspective of the domestic corporation making the payment, I would like to inquire if they can remit the funds as if they were paying accounts payable, and whether an agreement can serve as valid supporting documentation for that payment.