ForEach with Assign only returning the second looped aux value in foreach when sending from rule editor

We have a scenario where we use the best practice article of a BP and DTL to split up HL7 messages mainly ORUS 

https://community.intersystems.com/post/splitting-oru-messages-using-obj...

It is really useful but we have this code in many places that we are trying to consolidate it in one place. 

We do not want to split it at the first stage in our rules as there is a lot of messages that go to sink. So we are trying for specific rules and the incoming hl7 matches certain rules and classified for certain downstream systems that it is then split and transformed. 

The problem is that when assigning the value to aux.RuleUserData although the message is split up the value in the assign is always set to 2 when the send is being sent even though the value of Segment.{SetIDOBR} is both 1, and then 2.

i.e. souuce

first message is HSR2

The trace element is both 1 and 2 

The error is not the setIDOBR 

If I hardcode to 1 it will send the first obr out twice 

Why is assign not setting the value as both 1 and then 2 in the foreach as it is sending the message twice. I think this may be linked to the answer in https://community.intersystems.com/post/how-do-i-pass-auxruleuserdata-un... but for me I don't fully understand this answer. 

Is there a way to pass the counter of the foreach in any way to to DTL?