[REQUEST] Surface Laptop UEFI/BIOS with Legacy Support

As you know, Surface devices are well known for being Class 3 UEFI (Pure UEFI, no BIOS) which makes it impossible to install any operating system that is older than Windows 10. I would like to install Windows 7, and was wondering if it would be possible to mod the UEFI so that it supports CSM or Legacy boot. This might be a stupid question, but I’m new to this forum, so please understand. Thank you.