And file away your scanned papers separately,
I'd recommend using ASN (archive serial numbers) for documents you store a physical copy of, following the recommended flow
I printed ASN QR code stickers, using the smallest Avery labels I could find (Avery 5267 in the USA, L4731REV-25 in Europe) along with their free online design app.
For documents I want to keep, I stick a QR code sticker on them before scanning. Paperless-ngx automatically detects the QR code and sets the ASN. I then file it away in a folder that's sorted by ASN. When I need to find the physical copy again, I first look in Paperless to find the ASN, then find the document in the folder (pretty quick since all documents are sorted).
You'll need to set the following settings:
PAPERLESS_CONSUMER_ENABLE_BARCODES=true
PAPERLESS_CONSUMER_ENABLE_ASN_BARCODE=true
PAPERLESS_CONSUMER_BARCODE_SCANNER=zxing
