So you dont need to touch your config files, just use $_ENV in your configs - like laravel do it out of the box with many own variables als you can see in the config files - and create a .env for your different levels of deployment.
Keep this .env files ignored from git or others to secure your data
@samo basically some systems (don't know why) don't load or parse the file correctly and it will result in the default being used (where ever you call env('VAR')).
I am new to laravel and this forum. However I think that bashy has a point. I have same problem with database connection. Basically config/database.php ignores my ENV variables. I am probably doing something wrong. Or maybe not. That is the reason why I decided to "spam" laracas forums. :D
Thank you for your help though. I'll try to read documentation more.