I was hoping for a product that isn't a permanent swap. Then change over the HED rear disc from geared to fixed as I desire. Not daily, but leave it that way a week or two at a time. I maybe assumed incorrectly that parts for a quicker swap existed. On further looking, I'm seeing entire shaft/assemblies instead. Which would ruin my idea. I was hoping for a 5 to 10min swap.
In case I ever wanted to do the class and visit Rock Hill someday I would have an option. My TT bike, if fixed gear, already meets BB, crank length, horizontal dropout needs.
But if it's a permanent thing, I'll take a pass.