Do custom orthotics help with high arches?

They can: It depends on how this affects your foot function. Custom orthotics biomechanically control foot function. This can be used to help many types of feet and arch types.

Definately yes: A custom orthotic made to fit your foot will redistribute pressure across the entire foot, can ease heel pain, arch pain, even knee and low back pain. You need to see a podiatrist to have a cast taken. Don't use a cast where you step into a foam box- not accurate enough, either plaster or computer scan. The computer is not better than plaster- only neater.

FEEL BETTER: If made correctly, you should be more comfortable. Of course, your arches will always be high.