Leap 15 on Intel Atom 'power supply fuel gauge driver failed' endless errors

The ‘axp288_fuel_gauge’ kernel module is a battery monitoring for AXP288 power management hardware (PMIC device). It’s unlikely to be the cause of KDE crashing IMO, but maybe it wouldn’t hurt to blacklist it for now if it’s not working. You could also try starting IceWM session at the login screen perhaps?