I seriously doubt you would have any limb twist issues having that wedge laminated between your other core lams and glass... but... the difference between flat grain, and vertical grain is pretty large as far as strength goes..... With that being said.... I use a lot of walnut wedge stock, and ave had zero issues with it. It has relatively good stiffness...... It's using it in risers is where you need to be mindful and use footings, I-beams, and or laminations to help strengthen it. It's a rather brittle wood. .02 cents