I plan to save the output data in Excel for now.
What is your final destination for the data?It's not possible to avoid the attributeexposer if you need the attributes available in the workspace, but it is possibly to write them to a destination format without knowing them in advance.
Basically the same approach, but I prefer to use the BulkAttributeRenamer.
I'd use this sort of workflow - where you create new attributes based on the attribute values, expose them and then aggregate