Hi Pistol, I just wrote an article on this topic and bumped into your post here on the message board. Here are my thoughts. I'm a high-performance mindset coach and work very closely with professional supercross and motocross athletes. Feeling "comfortable" on their motorcycles is the #1 thing all racers are looking for in order to ride with confidence. I hear it used a lot in my world as well and feel it has a more action-based vibe to it and adds 10X to the word discomforts meaning.
I'm curious as to what subject matter you teach?
Here is my article on uncomfortability if you want to check it out.