Wish I could provide a little more information, but the reason we can"t use infrared has to do with a lack of control with the reflection of the beam. That"s as far as I can go with it.
Whenever we pre/post heat or stress relieve, we have to collect and store the data, and graph the process from start to finish. That can be accomplished easily with thermocouple connections.
I"ll bet a dollar we can get a vise up to 1200 + degrees in under a minute and prove it with some old school Miller powered induction heaters. Scary how fast that system is.