Why does everyone think that a turnback incorporates a 180° turn? It doesn't, it's 360°. Or near as damn it.
If you turned 180° from your position you will be on a reciprocal heading but North or South of the runway (should the rwy be orientated 09/27). You then have to make a 90° turn to regain the centreline, and a further 90° to turn to final. All this whilst that lovely wind has blown you round the turn, and is now blowing you downwind at a rate of knots.
In light of this I only teach my students to turn back if you have 1 commodity, and that's the height to do it. The height you would lose in the 360° turn will be significant (to maintain airspeed). I teach to pick a landing site within 30° either side the nose, and only extend this to 60° either side should you have no options at 30°.
End of the day it has already been said, you have to make a judgement call, because the engine doesn't know what stage of flight you are at, if its going ot fail it'll fail. You have to deal with the situation presented at the time, and they could all be different
CC