Need to confirm that lockbox allows application of a receipt across invoices from multiple customers

Oracle Receivables.

V 12.3.8

Lockbox functionality:

We want to start applying the receipts from the parent company across multiple invoices with children companies as bill to.

To my knowledge it is standard as long as we allow the application against unrelated transactions. We have been doing it manually in Oracle receipt application form but would like to start doing it automatically via lockbox file.

Is my understanding correct as long as we provide the billto customer number and the invoice number and applied amount in the record 4 in the lockbox file?

Will this have any impact on the MICR number in the record 6 for the parent receipts? Because the MICR number belongs to the parent customer on the receipt, but the invoices belong to the children customers, so we don't want the lockbox program to start adding parent MICR number to the child customer account.