I wanted a Thinkpad T470s to remember its keyboard backlight state across sleep cycles (and reboots). As ridiculous as it may be, this cannot be done through 1st party Lenovo utilities. So the next best thing were some github projects that aim to resolve this, the easiest one to use being lbcservice: https://github.com/JooJooBee666/LBCService - easy to install and will keep the backlight on. No remembering of last state though ;(