It is clear that Logos as a corporation has moved away from the conversion of public domain materials as being no longer cost effective for their core customer base. Some of the groups excluded by that decision have compensated by the extensive use of personal books to expand their base libraries most notably the Restoration Stone-Campbell movement and the German language resources. I suggest that Logos recognize that there are many languages and denominations and historical periods that are under represented in their catalogue and take advantage of their customer base's work by adopting select personal books as a fourth level of resources - between eBooks and Readers editions and allowing these resources to be fed into AI tools for searches, summarization, and translation. This would also solve the use across all platforms, duplicate storage when PB's are uploaded, etc.
Yes, I recognize that this divides personal books into two groups - those where the person submitting the resource can show it is in public domain or under creative license/voluntary public domain or authors' permission and those which must be treated as private until evidence of legality is provided. I trust Logos can solve the issues involved in a conservative manner that protects their legal position. And I trust Logos to be able to provide a reasonable interface to implement this … you don't need my ideas.