Does anyone know what kind of training Cirrus pilots get in terms of
when to use the parachute? I'm curious to know how it would compare to
the training military pilots get for using an ejection seat (which I'm
only slightly familiar with). Does either training syllabus deal with
gray areas, or do they both stick to something along the lines of "The
parachute/ejection seat shall be used under the following
circumstances..."

I would think that there is a fairly big psychological hurdle to
overcome for using the parachute or an ejection seat since you are
effectively saying there's nothing more I can do, time to leave it up
to fate. I'm guessing that the military tailors its training to
overcome this hurdle, whereas a company like Cirrus has to avoid
addressing gray areas for liability reasons. But that's just a guess.