I agree that 100K is too long. Plugs can get stuck. And i guess I live by the philosophy that doing maintenance before it’s required rather than wait until it’s required is a key to longeveity. Sort of like exercising and eating right before your first heart attack rather than after.
I generally recommend not reusing plugs. Many todaym those with the “flat base”, have metal compression washers on them that are designed for only one application. Once crushed, it’s not recommended that they be resused. Since I know you realize this, the comment is posted for the consumption of those forum followers who may not.