Datasheet PDFs + downloads, best pattern in Magento?

Three patterns, each with tradeoffs:

1. Custom attribute (file type): add a "Datasheet PDF" file attribute to the relevant attribute sets. Upload via admin or sync from PIM. Render as a download button on PDP with download tracking via Google Analytics event. Simplest, free. Limitation: one file per SKU per attribute, not great for products with multiple datasheets, certifications, manuals.
2. Magento Downloadable Product: gated downloads (require login) for warranty registrations or pro-only datasheets. Built-in but heavyweight, the SKU itself becomes "downloadable" rather than a physical product, so this conflicts with main electronics SKU type.
3. DAM + relations (Pimcore / Akeneo): store all PDFs in the PIM/DAM with relations to SKUs (one product → multiple files: datasheet, manual, warranty card, certification). Sync the metadata to Magento, link to the PDF served from PIM/DAM via signed URLs. Best at scale, 50k SKUs × 5 docs = 250k files, which Magento media folder doesn’t love.

SEO bonus: every datasheet PDF should have a clean URL (/datasheet/{sku}-{slug}.pdf), correct Content-Disposition (inline for browser preview), and JSON-LD on the parent PDP linking back to the datasheet as a DigitalDocument. Google indexes PDFs, they drive long-tail traffic to electronics pages.