I'm no expert on SPS, but my 10-month-old tank has gone through hell and back several times, as I've made every mistake in the book.
I once let alkalinity go way up to 1.032 for over a week, another time my alkalinity plummeted to below 5 dKH (did a number on my zoas). I've been fighting phosphates the entire time, with times it's been too high to measure on my Hanna checker (hence, over 2.0). I'd been doing good if I got it below 0.40 (though very recently it's been half that and sloooowly coming down).
Through it all, I have had a pocillopora frag that has lived through it all, but not grown much, and monti caps that have grown a bit, but not much. Same with some encrusting monti that has just recently started to show some growth. I also lost two other monti cap frags and some acropora frag that never stood a chance.
So terrible conditions for SPS, I know. Here's the thing -- I've had three different kinds of birdsnests that haven't just survived these disasters, but have THRIVED. I mean, they're growing like crazy.
So if my on-the-job reef training hasn't killed them off or at best stunted their growth, I'm not sure what would.