I used a nice feature in OC1 where if I had an config key under local/config.php it would overridde the base config.php value when on local. I see that is not working out of the box in OC3.
For your example, you’d use a .env.local file instead which overrides specific values inside your .php config files, which are now a single source of truth in terms of configuration. This is the suggested approach provided by Laravel.