Well, I just finished a PoC for integrating our GoodData analytics platform with MotherDuck.
Unfortunately, even though DuckDB states the similarity with PostgreSQL SQL dialect in their DOC, their dialect is much closer to SQLite ;-(
I am going to challenge them continuosly.
Meanwhile, someone would have to implement special dbt macros for SQLite dialect.
Can be quite complicated esp. in the case of date arithmetic.