Unlike in other softwares, in Xero you can have only two addresses per contact.
We convert the first two contact addresses, unless there is another address that is a PO Box. We prioritise the PO Box for use in the postal address.
The other addresses are not kept.
When creating invoices, it is also possible in MYOB to choose a shipping address from a different contact card to the billing address. Xero does not allow for that and you will only ever have an invoice connected to the one contact with its postal and street address.