The version with -loader suffix will try to search and load EFI\Microsoft\Boot\bootmgfw.efi so it can be used as a normal UEFI boot entry. (It does not verify the authenticity of bootmgfw.efi, so even if you managed to launch it with Secure Boot enabled, the trust chain will be effectively broken.)
I don't have any computers with a WPBT, but at least 1 user has reported it working correctly.