Yes, okay, that's all fine and bewt when you can practice it in a sim. What about all us blokes who fly things like Kingairs, for whom a sim session is mooooost unlikely. How do we practice for that sort of emergency?
We don't. Because we can't. Thus, our own personal sphincter spasm activity is what we tend to have to rely on all the time. We ARE forced to consider field length and the liklihood of getting visual, but the reality is that none of us want to go down in a ball of flame because the fire got into the wing tanks, even after the extinguisher may have killed the engine fire.
Too many unknowns as far as I'm concerned. In any event, there are so few places around here that have credible fire or other emergency services that I'd probably end up taking a chance on getting visual and landing - without making any significant configuration change. Yes, there are, obviously, circumstances that'll alter cases but, if the approach is runway-aligned, I would probably elect to go for it.
That said, the only approach here that gets an aircraft below about 500 feet AGL is an ILS. Thus, the chances are that we're more likely to experience this critical situation only on the ILS. With any other type of approach, we're either already visual, or already in the missed approach when it happens.
So, okay, we're below 500 feet and still in IFR conditions. I've got a VERY serious problem but I know that the ILS will deliver me to the runway. Remembering that this is a major emergency situation, it will come down to whether or not I have the balls to flare and land on the runway in IMC. I suspect that, on the balance of probabilities, this would be the least of my troubles at the time.
But, as has already been pointed out, making the really big decisions is the reason why we're called "captain".