Usually toe grinding relieves point pressure and heel grinding covers a wider more general area. Smooth and nice heel cup grinds take some time to make nice- costs some bread. Toe grinds are quick and common.
I think happy toes are important. There is no reason- ever- to have cramped painful toes. Jackson Hole is a cold mountain, and toes space equals warmer toes and comfort.
Can you get the volume smother way- like grinding the zeppa or thinning the vertical volume of the orthotic/insert? Thinner socks have substantial effect on boot volume. Don't mess with the shell if you don't have to.
Slightly off topic: I was in the right place at the right time yesterday when they opened the Headwall , a popular inbounds bootpack above the Cirque. It was about 8º and sunny. Cold temps = good skiing in places like JH. Keep those toes happy, mine were yesterday and they have roomy comfort. Ski boots have changed, tighter medial lateral fits have made roomy toe boxes possible.