Hi doconnel: what is the end goal that the customer is after? To do what you've suggested sounds like you'd have to come up with wonky calculations that replicate/defeat what OneStream's natural elimination funtionality already does with plug accounts.
For my company, we needed to do (and continue to do) training on how the eliminations work, and how the accounting team can use the Consolidation dimension to view most things they are after. A layout of C#Local, C#Translated, C#Share, C#Elimination, C#Top can a powerful tool. Granted, depending on the parent entity the currency may change, but that could also be solved with a UD8 to force everything into one currency.
This is probably not the answer you were hoping for, but I'd try and understand their end goal first, and see if you can demonstrate how out-of-the-box functionality might be able to meet their needs without needing to modify consolidation.
-DB
