Currently, assets are configured using keys like assets.*, but these should probably be in the play namespace, e.g. play.assets.* Also, we should add the configuration keys to reference.conf.
Just a note: Whoever puts assets.checkForMinified in the reference.conf please don't set it to true or false - just comment it out or set it to null - so we can be sure the default behaviour will be invoked (which is false for dev and true for non-dev modes)
Yes, the new convention now is to set to null if there is some special default behavior, and add a comment explaining what null means in the reference.conf.
Created a PR for the task - #6348