It is a very hard call to make.
I've seen passengers wander off home to pick up something they forget when a flight has been disembarked (domestic obviously).
But organising passengers is like herding cats at the best of times!
But then there are things like is there a gate for you to return to, or have you been directed to a standoff.
Your engineers try their best, could be 2 components, one is 45min to change other is 3hrs - 45mins in the seats is preferable to get them off, they disappear, get them on, but if that doesn't fix it then its 3hrs, except what do you do if you're on the standoff?
Like had been said, damned if you do, damned if you don't.