If you have an Android phone, you can download the Google Translate app and then download Korean and use the camera icon. It will translate from Korean to English right in front of your eyes.. It's really cool.. it overlays the original Korean text with the translated english one.. works great.
As I would have suspected, most of it has to do with body and infotainment functions, nothing about the powertrain.. The Prius had a similar secret screen-set, largely useless with regard to driving. These things really are IoT devices that happen to sit on a propulsion system, aren't they... _H*
I would have been very surprised if the engineering mode would have given anybody access to charging management..