Specified environment variables into config.json

Instead of always giving precedence to pre-existing config.json entries, is it not a better idea to give precedence to set environment variables? And then I mean overwriting entries in the config.json whenever environment variables are specified on startup.

I already do this in a patch script myself for admin_token/ADMIN_TOKEN, when I want to specify a new one on startup. This doesn't preclude usage of the Admin page, they can be used both, and doing things this way would make more sense to me.