You may be out of luck for now. https://github.com/sddm/sddm/issues/1399

The record is for panel efficiency, whereas the 28%, 32.5%, and 47.6% values you refer to are about solar cell efficiency. https://energytheory.com/solar-cell-vs-solar-panel/

There is a section here on dual booting using systemd boot. Never used it, but it will hopefully work in your case, or at least point you the right way.https://ostechnix.com/dual-boot-windows-and-pop-os/

Bodhi Linux. Lightweight and beautiful