Slippery Pete,
Very well said.
Your comments re strict criteria for control of and termination of the exercise are spot on. That is what is required in all training scenarios but especially something as critical assym work at the very edge of the envelope and close to the ground.
Again doing so in the sim is best and safest in these TKOF scenarios.
As you say it is never worth dying for to practice some extremely unlikely scenario that out of hundreds of millions of TKOFs worldwide over decades an EXTREMELY small number of flights have ever experienced.
Also for everyone out there who has seen the variety of FAA definitions of V1 that have been published over the last 30yrs here is the best one I have seen that is most accurate and easiest to remember--
V1
"The speed at which the takeoff must be continued, if the abort has not already been commenced." 
V1 is NOT the latest speed for a stop decision, V1 is a GO speed, the difference is significant and critical. The failure must be recognized and the decision made before V1.
I have the article explaining those statements in a file, if anyone wants to see it just pm me.