Sonex is using a SSR in their high wing. It's in the story here:
https://www.sonexaircraft.com/highwing-update-040725/

The Sonex team is also experimenting with the use of a solid-state master relay, saving weight, eliminating moving parts, and reducing relay power consumption to a maximum of 13mA (0.013 Amps). The solid-state relay is performing great so-far and we’ll continue to monitor its performance as we begin engine runs and start flying.
I would not be surprised if they offer it for sale on the Sonex Web store if it works out.