@Liam Wood: Is there any solution or approach which you identified for the same? 

Liam Wood  / @David Marcus  Or anyone in the community:

Even, I am also facing similar issue where multiple participants are being onboarded and what we found is that, there are few lab results under participant CDA result sections, which are being mapped to HS.SDA3 RadOrders-->RadOrder-->Result instead of LAB Order

Also, multiple observations under same entry Organizer is being appended under RadOrders-->RadOrder-->Result-->ResultText 

e.g. 

<OrderItem>
                <SDACodingStandard>2.16.840.1.113883.6.1</SDACodingStandard>
                <PriorCodes>
                    <PriorCode>
                        <Code/>
                        <Description>CBC w/ auto diff</Description>

.......

.......

<Result>

    <ResultText>WBCred blood cell count (RBC)hemoglobin (HGB)hematocrit (HCT)MCVMCHMCHCRDWplatelet countneutrophils automatedlymphocytes automatedmonocytes automatedeosinophils automatedbasophils automatedimmature granulocyte automated</ResultText>

Any pointers can help.