Hi,
2000 is not that much, you actually could use that assistant, in batches of 100 documents. For sure, it might take an hour or so, but it's not very hard.
We have another assistant that should accept more files, it's called Create Documents. I think it might be a little bit better, but it's also not meant to import 2000 files in one go.
You could migrate the documents by calling a Premium REST API that we have called CreateAndImportDocument, but you need to use some tool or script and writing that might take longer than to do the work manually.
You could also try out this approach:
https://community.ifs.com/ifs-document-management-employee-partner-only-257/document-management-data-templates-20843?postid=76992#post76992
Good luck!