Using ALEAUD for application reply? or build a new IDOC ?

Hello.

I have a scenario where a 3rd party sends me a message, that I map in my PI to an ACC_DOCUMENT IDOC.

I need to send a reply on the ACC_DOCUMENT IDOC after processing it.

The reply must contain several applicative values from the IDOC - so that the 3rd party will be able to

"understand" on what message it receives the reply.

Should I use ALEAUD in this case? I'll have to add an extension so that it will contain the applicative values.

Or should I build a new IDOC or ABAP proxy to send the reply back? will I be able to generate it when I process the IDOC?

Anyone has a Rule of thumb on this matter?

Thanks in advance,

Imanuel Rahamim.