I'm not able to reboot my surface with a uefi usb neither sd card as they appear as USB Class Device not UEFI USB. I'm attempting to make a clean install and can't access my bootable usb device. The usb flash is booting right as I tested in another machine that has GPT UEFI. I turn off, on and off again the secure boot. My guess is that my firmware counting the number of bootable devices wrong and I would like to reset it. Is there anyway that I could reset the firmware or re-installing cleaning it's ROM?
There's another way of booting a USB device besides going into the bios that's through configuring the windows boot manager BCD with EasyBCD. I create an active removable flash in DiskPart copied the files contained in the window's 8 iso there and added in the windows boot with easyBCD shown here. It's good to delete the boot devices that appear in the Surface Pro's bios that are not longer used but careful to not delete the boot currently been used by windows otherwise it won't boot. After I deleted the boots that were no longer used I was able to see the USB Flash UEFI properly to be booted.