Adding a Snowflake connection configuration option that allowed for standard Snowflake connection conventions might be a good option. That way you could connect to Snowflake with your existing configurations (.snowsql/, .snowflake/). Or explicitly specify by adding matching args/params to your project's config.
I just pushed the external_browser branch to github that should offer 1/ externalbrowser authentication and 2/ the ability to use TOML files with profiles with instructions on how in the readme. if you run the following you should be able to test it out.
git clone https://github.com/ryanwith/melchi.git
git pull external_browser
# remaining steps are the same
Would you mind testing it out and letting me know if it works for you? Would really appreciate it!