Good question! This is the definition in the rules, which I think is the same for USA and IUF Rulebooks:
“Ultimate wheel: A special unicycle consisting of only a wheel and pedals, with no frame or seat.”
My interpretation of this would be that the leg supports on the Lunacycle could be considered a frame, at least in terms of comparison with a “regular” ultimate wheel. In other words, the intent of the Ultimate Wheel race is to have “plain” UWs that don’t have leg supports. This will have to be addressed in the future.
The Racing Referee at each of those competitions should have the final say on how it will be handled under the existing rules. Were it up to me I would not allow the Lunacycle because it has a distinct advantage over a traditional UW. Then should follow an update of the rules for UW racing, to be more specific about “leg supports” or similar, and how they should be considered in the future.
I just read the older thread, to learn that the wheel on these things is not round. This would help with the learning process, and might actually make it easier to learn than a regular uni. But if you wanted to go fast on one, the non-round wheel would be a detriment. At typical UW race speeds, it could be a big problem. I still wouldn’t allow it to race, but it might not be that big of a difference at high speeds.
If I may dare to predict the future, as soon as you make one yourself.
I’m fascinated by this “improvement” on the basic Ultimate Wheel, and tempted to get one before they’re gone. It’s a novelty thing, that will appeal only to a pretty small market, and is unlikely to keep being produced unless they have strong sales. Get one while they last!