Thanks! And great idea. I haven't deep dived into DuckDB's storage format yet, however I know that they split up the data into row groups which internally are columnar. I'm not sure how that maps to the pages in the file. If it doesn't align well, or they do a lot of shifting style writes (writes that cause all subsequent data to shift forward or backward) it may not be a great fit for Graft.
Either way, it's 100% a great idea that I'd like to explore. If any DuckDB contributors are reading I'd love to know if it would work!