Key shafts went away on USA domestic cars in the 60's, absolutely no need for a key.

However, I see a strong possibility that the hand tightened by holding fan / epoxy / locktite mess will come apart down the road.

The no key shaft works fine when the nut is torqued to spec as the pulley is trapped between the nut and rotor. Our guy hand tightened the nut so eventually the pulley will fret and spin on the shaft. Being the nut was locktited the nut will still be in the original position ( RE the nut didn't back off, the pulley got thinner from wear. )

At that point our guy posts that all non keyed alternator shafts are doomed for failure, when in reality it was an assembly error.