You can totally select a different kernel if it's packaged in its own EFI payload. You can even enroll this EFI payloads from within the BIOS by just selecting

You can totally select a different kernel if it's packaged in its own EFI payload. You can even enroll this EFI payloads from within the BIOS by just selecting the file from the EFI partition if you forgot to add them into your UEFI (ie if they don't show in your F12 boot options)