Genuine question: why?
Have you ever heard of a coaster having a bad incident whilst in its testing phase? Personally, the worst I've ever heard of is a train stalling; something which can happen at any point really.
Outside of that, it's no different to, say, a car being built. Heck, the train itself is barely any different to a bike, minus the restraint. And whilst the train itself is new, it's no different to any other train built by RMC, and is easy to test.
Don't get me wrong, I understand it's a quick turnover. And you're probably not the only one who wouldn't feel comfortable. But outside of the time frame, is there any reason you wouldn't feel comfortable?