The EPL is there for when the throttle linkage breaks and the power lever won't work any more. You won't get any more power out of the EPL that you would have with the throttle.
It's been a while since I've flown one but to memory that's how it worked. And yes if terrain is imminent then you firewall and hold your balls.
Secondly, why do you want to feather after an overrun?
RC.