In my opinion, SSS does nothing to show if you will actually beat said boss, or even if you'll make an enrage. So it blowing up isn't necessary, watching it fade away with whatever percentage it had left should be enough.

It's just you, burning a dummy down, that's it. No mechanics, no adds, no AoEs, no falling off platforms. I agree it can be used to hone your rotation, but any indication that you will pass or fail said instance is just not there. All this is, is a better version of the training dummy you may have at your home or FC house...