Handling ORU^R31 and ORU^R32

[PPFH]

Hello,
In our project we encountered a device sending ORU messages with Event Triggers R31 and R32. The device also expects from the HL7 Server a default ACK in response to ORU message and then a ACK^R33 message.

Example of Server<->Device communication:

LIS-HL7 Server      -----    Device
                    <----    ORU^R32
 ACK (ORU^R32)      ---->
 ACK^R33            ---->  
                    <----    ACK (ACK^R33)

I'm not a HL7 expert but I read that triggers R31, R32, R33 have been introduced in v2.5 or later.
The device ORU message's MSH declares HL7 v2.4: clearly this is an "out of standard" protocol implementation.

We are using Hapi HL7 v2.3. Unforntunately I see that those event triggers are not handled by your library yet.
Is there an easy way to handle those messages and to send a message (ACK from HL7 Server to device) without expecting any response?

Note: I must say that I actually found a way to do part of the job (handling ORU^R31 and ORU^R32), however it's far to be a clean solution (it's just a workaround but it works).

Thank you very much,
Andrea