I do not DD. At least what you are thinking of. It will be interesting to see what others have to say.

You said..."Seems there is a generally accepted standard as to 10% length reduction and then testing by twisting to the breaking point of the material being used"

I'm not sure that is an accurate statement.

It's all about tension... it can be applied a number of ways. Let's use the hand held powwer as the example as I believe that's what you are talking about. BTW I know someone who can get up to 17% reduction doing hand held power and applying the correct tension. 10% is an easy target and puts out a nice leader.
But what the folks are doing is applying what is felt to be adequate tension while twisting up to 10% reduction and stopping.... during that twisting the energy is being stored . They have applied enough tension that they are close to the breaking point without pigtailing at 10%.

I think you might consider this. Use your torque idea to determine the breaking point of a given material and leader formula and then set future torque so as not to allow breakage before you got to your desired reduction.