I have a spare rotor for my mono ml somwhere, but no stator - and, of course, its the stators that die. I cant see a rotor ever dying from the amount of veg / glyc etc that i pump.
Ive always been careful to flush through with veg after pumping glyc, but i had an air leak on the inlet a while back, and it was running for a while, and i think some of the magic smoke has escaped from the stator. It still pumps fine, but is a pain to prime.