My own experience was that I dealt with ulnar nerve RSI for about a year. During that time I wore braces at night and tried just about every keyboard and keyboard layout imaginable, and at best I managed to keep it at bay. When I finally made up my mind to go to physical therapy I learned that:
1. I had postural issues which led to trapping the ulnar nerve in my shoulder (not my wrist, that was just where the pain referred to)
2. I had deep myofascial issues that were preventing my muscles and nerve from moving freely in my arm
3. I had poor mobility which was contributing to decreased function overall
Where I thought I had a localized problem in my wrist, it turned out I had a systemic problem which required strengthening through my entire arm, shoulder, back, neck, and core. I resolved these issues through physical therapy and my ulnar RSI hasn't returned since, though I now maintain an exercise routine that focuses on mobility. I still use an ergonomic keyboard, but I'm now convinced that the issue can't really be solved with gear.