Yeah I've been wanting more flexible auth support in httpfs for years now but am just coming to the realization that often for cases I encounter, auth tends to be more complicated!
Direct reads out of Snowflake are also probably not going to happen anytime soon.This extension looks neat if running standard DuckDB; saw a few weeks back.
Check out Snowflake Iceberg support however; you'll be able to read that soon natively with DuckDB; Motherduck inclusive.