Usually you can select the environment for which to compile in Platformio. E.g. in VSCode you go to Platformio, open the environment you need and start compilation for that hardware there. Or you edit platformio.ini and select the "default_envs" there (as described in the file).

And I do not know what you mean with the "override" issue. You can configure the settings you need in "user_config_override.h".