Does "PilotEject Plugin Event Weight" override Pilot Eject's own setting "Chance of game spawned helicopter becoming a PilotEject helicopter"?

Will not override.

But why "PilotEject Plugin Event Weight" then if there's already a setting in that plugin for that?

This is a weighting...

Event Weight: The greater the relative weight, the more likely this event is to occur.

e.g. NormalEventWeight is 60, FancyDropEventWeight is 30, PlaneCrashEventWeight is 10. Then the NormalEvent has a 60% probability of occurring.

Oh. So this is meant to work with all different kinds of events if they're true?
So, we should manage to not have over 100 overall?

Weight is relative.
    NormalEventWeight is 3,
    FancyDropEventWeight is 2,
    PlaneCrashEventWeight is 0.
Then the NormalEvent has a 60% probability of occurring.
Each time an event needs to be run, an event type is selected based on the weighting.

Ok. I have no idea what this means and what it's for. :)
Well. Don't mind.
I will find my perfect setting somehow.