I (with others) made a Python utility for loading data into PostgreSQL incrementally from ETL-ish pipelines. Its API supported ingesting into multiple multiple tables at the sort of "structural" level from its beginning (more or less), but didn't actually support it if you tried to do it. And I've been umming and ahhing on how best to do it. No way seemed perfect...... but pushed by an actual use case, I finally made a decision and did it.