Temp is more important than curie, it’s just a handy coincidence for basic steels- go with the IR thermometer and aim for 800I actually have an IR thermometer which measures up to 1200 deg which I use for my home made foundry. But I guess this isn’t about temp as much as the Curie point, so the loss of magnetism is the key.
I like the idea of hotter oil for quenching.
thanks