Personally, I am not fond of trigger finger rests. They make my index finger colder, like you said, and stress my hand in a way I don't like.
However, a pinky rest on ice tools is super helpful for me- it allows my weight to be where I want it. Keep in mind that I have (essentially) the exact same tools as you (Thanks again, Curt! They've gone a long way!)
It really varies from person to person. Find what works for you and stick to it.