Have you tried using brown rice syrup or golden syrup in place of corn syrup? Do you think it would be a 1:1 substitution?

I'm wondering why you are doing this - is it because you are opposed to high fructose corn syrup? It's not the same thing as corn syrup. Just use the real thing! Brown rice syrup is strongly flavored and will provide a different texture in baking

I used Scandinavian light syrup (made from sugar beets) at 1:1. It worked great, but my cooking time was closer to 6 minutes rather than the 10 in the recipe.