I know this would never fly, but I think the quid pro quo is reasonable. Author must offer the book for first refusal, Publisher must publish at agreed floor rate in constrained time period.

This would approximate the apprenticeship system where artist and audience are bound together. If a publisher knows they don't want to publish any book the author writes, they should be real clear as to the limits of what they will consider for first refusal, and free the author to write on other subject matter.

bv