So I had a chance to try this out. It wasn’t on Google Play Store, only F-Droid. There isn’t really SSO support, you either login with User/Password or a token. Instead, I login with my browser, get the token and paste it in. That works fine, but an ideal world is just pop up an browser WebView and go through the flow, then grab the token. Maybe it was intentional, but PaperlessShare registered as an Open handler for PDFs and the share menu, whereas this is only share menu.

Overall, it does the job and gets my docs uploaded.