Thanks for the replies.
I’m wondering whether it acts like a keel on a boat in some way, perhaps helping to keep things moving in a straight line.
I would love to hear more about other people’s experiences with a disc wheel, especially if you noticed the difference between using one and not using one.
I will try to borrow it again for another ride.
I’m hoping it is true before I decide to spend the $$$'s or $,$$$'s.