I’ve ran a transitional lens for over a decade. It just isn’t ‘instant’ but the trade off is I don’t have a solar panel sticking out from the front of my visor.
And while other chemical-based photochromic visors that engage when hit with UV rays exist, they can take close to a minute to transition, or become activated even in cloudy conditions when they don't need to. When light hits a solar panel mounted at the top of the visor, it immediately powers the visor's liquid crystal film for an instant transition.
My understanding is transitional lens aren’t legal for road use in the EU/UK either. So thought it was odd that an Italian company was making these…then
The co-branded visors can be fitted to Race-R Pro, Aeron GP and Aeron lids, generally suited for track use.
I had two motor options when I test drove my vehicle. One had start/stop and the other didn’t. I drove both on the same route. There was a freeway exit that was one of those slightly irregular yield right handers. I had to stop for maybe a second for a car to clear. The engine shut off. I hit the gas since it was now clear for plenty of time till the next car. It didn’t move. I hit the gas harder. Nothing. Now it’s starting to get questionable with the approaching car. Hit the gas harder. Then the engine finally kicks on when I’m in the accelerator about 50-75%. The vehicle squeals its tires as it pulls away. The sales person doesn’t really say anything from the passenger seat. That was my first and last time dealing with start/stop. I bought the other motor option.