I'm still puzzled. If I try to look at the scenario you're suggesting, it seems that a SEIFR is conducting an ILS in IMC and, at some point in the approach the engine fails. Is that about the size of it?
In that case, why not consider the engine failure as you pass the FAP?
See, no matter WHERE the engine failure occurs, there's not much you can do about it because the aeroplane is going to go down. And it'll go down much more steeply than you're nice comfy 3-degree ILS path. So it's like I said yesterday...
There aren't any choices, so you do what comes naturally... crap yourself, kiss your ass goodbye and hope for the best.
Not that I actually fly SEIFR these days... I've had enough problems with engine failures in singles, earlier in my career, even in good weather, to see the folly of SEIFR. However, in those days, I would ALWAYS fly the approach to the DA/MDA, unless getting visual higher up.
You might find it useful to check out topo charts in advance, to get an idea of your chances of surviving your scenario. There are, of course, many places around the world where it's actually better NOT to know what you're going to hit in the event of an engine failure!
