INTERNAL: Can only upload 1 file to a Library with over 5000 items
Using qListForm for a Document Library with over 5000 items (and a lookup to another LARGE List), you are unable to upload multiple files and can ONLY upload 1 document at a time.
Due to multiple Technical issues, there will not be an Enhancement Request for this issue and this scenario will be unsupported.
The List Threshold for the Library/List has been reached.