The problem with eye-level viewing is in the past, now you can get a <a href="https://www.tranquilmount.co.uk/product/tmo400a-fireplace-pull-down-tv-mount-40-50inches/">Pull-down TV Mount bracket</a> from TranquilMount to resolve this issue.

I would use a gas spring TV mount that allows you to push the TV above the fireplace and back down for eye-level viewing.

This mount I use is called tranquil mount