Is there a way to generate multiple Excel workbook using only one Writer?

I have to generate approximatively 850 Excel workbook and I was wondering if it was possible using only one Writer or if I had to use 850 Writers.

I thought of the possibility of generating 850 sheets in one Excel workbook, but I would have trouble actually opening the workbook with my computer (lot of memory used).

Also I work with a 2017 version of FME (I stumbled in the past on issue that could be esaily resolved with 2018, but I had to work in the limit of 2017).

Thanks