Hello Rodrigo, sorry for the delay in replying. We do have in excess of 1700+ documents, each being attached to an individual DIR all residing under one folder.
On trying to access the folder to reveal / access the documents / DIRS, the response time is extremely slow. Often minutes. The recommendation from Sap is to create more sub-folders [FOL documents] to further categorise the documents. No more then 800 or less as you have seen.
The problem being that on accessing the folder, Sap attempts to open all the documents residing under the folder, to determine if the user has authorisation to access them all.
We have not currently done this but intend to at some point. Other priorities etc.... Users are currently living with-it.
We very nearly did this at the out-set but users felt it an over complication with so many sub folders when really one was deemed sufficient for their purposes. So I would go with Sap recommendation. I hope this helps you. Again apologies for the delay in replying.
Regards
Gary.