TR3 not sure I entirely agree. Yes SID's are generally drawn based on all the A/C eng's operating, and most specify a min climb gradient. However SID's can also be constructed with noise rather obsticles in mind, and in cirtain cases it may be better to fly a sid with an eng out knowing where you are rather that fly straight ahead IMC. Of course only if there is no emergency turn published.
I think I am correct in saying ATC may not always be aware of emergency turn procedures so advise.
Best Rgds