It’s my understanding that the 18 year clock starts when the manufacturer sells the airplane, and that the law applies to all GA airplanes, including EAB’s. So when Cessna builds a 182, the statute time doesn’t begin until the plane is sold - by Cessna, even if it’s years later.
My former hangar partner, who built an RV8, moved away from Ohio to Connecticut and of course took his RV8 with him. After flying it for a few years, he sold it to a guy in Florida. After that guy had it and flew it for 8 years, he had a catostrphic inflight engine fire and tragically lost his life. About a year later, when the final NTSB report came out, my hangar mate was sued by the survivors of the victim of that crash. It is unknown how the airplane was maintained or operated during the 8 years after my friend sold it. The engine had come apart internally and punched a hole in the crankcase, causing an oil fed engine fire. The attorney that filed the lawsuit was from Texas, and I suspect an ambulance chaser that read the NTSB report. He also filed suit against the engine builder (ECI or Superior, I don’t remember), Hartzell, Champion (Slick mags), and a few others. The point being, you can be sued for things that are beyond your control. I’ve read on this website and other places, that no one has ever been sued SUCCESSFULLY in an EAB lawsuit, but you still end up spending tens of thousands of dollars defending yourself. I don’t blame the OP for wanting to destroy his RV6A rather than sell it. He also needs to make sure he de-registers the airplane, and destroys the data plate on the airframe, engine, or anything else that has a data plate.