Specifically, does it allow you to attach files, and/or have an archive of saved files? How do people using paid subscriptions handle PDFs attachments? Can it be done via Dropbox, or is there something inside Substack itself?
Hopefully these are just academic questions. Alas, hope is not a plan.
1. Attachments, yes. https://support.substack.com/hc/en-us/articles/4408381643156-How-can-I-attach-a-file-to-my-Substack-post
2. This includes PDFs.
3. It’s inside Substack