Might look for a large, lightweight cutting board, altho I don't know the dimensions and if something that size would be available.
I have a glass burner cover on little legs that sits over our two-burner cooktop, that I found at a Kitchen Collection store in an outlet mall.
It fits perfectly, covers the burners which otherwise came with no cover, and adds that extra counter space.
If all else fails, might find a woodcrafter to custom make you something,
🏡 🚐 Cherish and appreciate those you love. This moment could be your last.🌹🐚❤️