Hi Daniel,
Perfect understanding.
Meanwhile start doing/maintaing technical doc, make it the fields which you have got from RSOSFIELDMAP(ecc feild to bw object).
I think your data flow design was over, if yes, you can name the fields which you have used.
if you missed some fields which are not available in RSOSFIELDMAP, for those, you can assign sap defiend one or custome defind bw objects which have same lengh and type of ecc fields. that would be useful.
Thanks