apparently the fbsd loader efi is supporting 32bit i386 as well, so similar update as done for amd64 is needed to make it possible for efi_console to recognize and translate box characters on i386 build (unsigned versus signed char passed as int issue).
Im pretty sure the arm variants have the same issue *if* bootforth is used there. The defect itself is manifested as menu frame (box) is not drawn, so it is easy to verify if such type cast is needed - unfortunately I don't have resources to check arm, hopefully someone with access to platform can check...