How often do you have to un-button the driveshaft?
It's a cost versus benefit analysis
cost versus risk analysis
It's it's $6 versus catastrophe and you do it every 10-20 years I'm not sure I appreciate the argument for re-using the old bolts.
One of the risks of these bolts letting go has to be death as well. I never tempt fate with Clutch Bolts or flywheel bolts either.