Hi Alex,
Isn't this forum where I would ask other store owners? If so, consider the question asked.
It wasn't the number of products being updated, it was creating/updating the HTML to be well-formed in a cell in Excel to ensure it remains in the proper column.
If a mistake is made with a comma outside of a quotation mark, it becomes pretty simple to break the upload. Plus updating those HTML descriptions has it's own challenges when considering updating several (100-500) products at once.
At this point, we either have an HTML document with sections (using ID's) that includes the short description and the expanded description. I can extract those HTML sections by product for a given upload and write directly to the MySQL DB or add these sections to a csv (Excel file) based on the sku.
But still working out the management for my client.
Thanks.