MSD is a so-so company. You can look to see where they are located and that should tell you plenty.

That said, there's no reason a digital device can't work off a sine wave. It happens millions of time every day in all sorts of applications. Don't forget, almost (and I mean basically all) AC power is sine wave power and there are hundreds of thousands of digital devices working in harmony with them. I'd bet a Hemi Daytona your house is powered by sine wave power that is regulated by digital controls.

Do you mean it won't work at all, or it won't work properly? Does the car start and run poorly or not at all?