The CTRL ONE recently got Made for ESPHome certified! It means not only that the firmware is fully open source, but everything you need to configure and customise it is too. It also works perfectly with the ESPHome Device Builder.
It joins the list of many other simple devices that integrate perfectly with Home Assistant, and meet the ESPHome team's criteria for open devices that you can fully configure. To make it possible, I contributed code written for this e-ink display directly to ESPHome, and it's all maintained in one place.
You can find the new page here! https://devices.esphome.io/devices/elvinhome-ctrl-one/