Does Bird supports AS_Trans 23456

Hello everyone, Does anyone know or test the AS_Trans 23456 with Bird? We are using Bird and our ASN is 4 byte, but the peer supports only 2bytes ASN. I told them to use the AS23456 to peer with me, but it seems Bird doesnt establish session with the peer and Im showing "bad asn" So does Bird support this feature? Should I configure anything in Bird so it can send the open bgp message with ASN23456 instead my real ASN? thank you, Gerta