If you are going to teach/practice ETs then it goes without saying that you observe anu a/c limitations - indeed this should be part of the brief - surely good information for any student?!
In reality if you HAD to do an ET then it may be a choice between a mid air collision and the RISK of overstress etc - I know which I would prefer!
I think it is unfair to let pilots loose without giving them some form of escape route. A pukka steep turn is not the same as an ET. Practising ETs shows the students that it may be necessary to fly the aicraft decisively to avoid a collision and given the traffic density and mix of traffic in the FIR I think it should be taught now. I wonder if any of the collisions that have occured between military a/c and civil MIGHT have been avoided if the civil pilots had had this training?