One feature which seems to be quite a nice improvement (speculating as I haven't upgraded yet) is consumption templates [0]. My workflow involves an ADF scanner with an Android application, sharing the scanned PDF with Paperless Share [1] and then it's uploaded to the server via API. It seems that consumption templates will enable adjusting tags/sharing settings/permissions of a document at ingestion time based on where it's ingested from.
[0] https://github.com/paperless-ngx/paperless-ngx/pull/4196