Ref Brian Abraham's link, my first thougt would be that at low rpm and full boost you would get more torque than at higher RPM.
As to the T6, I trained on them and instructed on the less powerful (400hp?) Piston Provost. Over one year I do not recall any accidents at our T6 school caused by torque roll, nor do I recall any problems personally. The one time I had to slam to full power was in a PP at very low IAS and I got much more yaw than roll.
Mind you, our Canadian instructors, with time on Mustangs, did consider torque roll to be a killer, but there you are talking 2000hp.
Dick Whittingham