Mounting a center channel speaker on top of TV is a bad idea. Look for a entertainment stand with center channel shelf. Check out Salamander Designs. I have two stands from their Synergy collection, very high WAF 😊
https://www.salamanderdesigns.com/av-cabinets/elba-236/
https://www.salamanderdesigns.com/av-cabinets/elba-236/