Plasticrake, if you are still around, would you be able to add support for KS240 device ? I don't have device myself and I'm not expert at all, but it could be dimmer with childIDs like HS300 plug maybe ?
There is ongoing discussion on HA thread, if it would help.
home-assistant/core#111238
https://www.amazon.com/Kasa-Smart-Adjustable-Brightness-KS240/dp/B0CTDCQJVZ?th=1

Thank you for your support