Those of Vat. II refused to define any of their schemes. Where is infallibility? NO where! When infallibility is used, rarely, it must define. For those to do so, in Ratzinger group, would prove them heretics.
As for indefectibility, it means what "Christ instituted", not what man made up. For another example, The Precious Blood" will end. On the earth it is known as Continual, and Christ Blood is Eternal.