For those of you in AUS, if you are with Q, then you have the tailored departures to work with for OEI. With those, you can see the different flightpaths, and there are some that do not meet the "straight ahead until" parameters of the SID.
I actually wish that ICAO or the FAA would come up with a DEP criteria, but alas, I dont see that happening.
Tailored procedures used the 10 year high temp, and a combination of MTOW, all the bleeds turned on, and the engine type 20K/22K etc...spec. (5, 10 sec...)
The EO DEP are designed this way, adding turn performance, for the basis for the different NA above restrictions.
You have a 20K, 5 sec motors, its hot and you are heavy, you are going to be at double digit climb gradients....