I put the TV on a separate wall than the wall which will eventually have a wood burning stove. (The mantle and backdrop is already in place. Right now I am dealing with homeowners insurance that doesn't want me to have one.) I don't watch much TV at all, and I really dislike - for me - having an ugly black box being the center of living room attention. When I have guests over, we're here to talk. I can think of exceedingly few occasions I'd be watching the idiot box with guests. Probably if they were here several days, we'd rent a movie or two via Amazon Prime. (Moot point right now, COVID and all.... but hopefully that won't last...) And with a wood burning stove, the exhaust pipe will go up and bisect the view of any TV over the mantle. I sat down on the couch to figure out the best viewing height - which is well below what the mantle might ever be, at least on this couch. It would be fine if I could lean back and rest my head, to have something over mantle height - assuming I'd go with a regular fireplace. But at six feet tall - there just isn't a couch or sofa like that. Plus as others have said, what about decorations? I enjoy decorating my mantle for various holidays! After all, that's really what mantles are for, right? The thing is off to the side, and it does not get glare there, either.

I was at a friend's house and they had a built in similar to yours. They had the TV on a sliding shelf in the built in and pulled it forward for viewing , but then had the option of pushing it back all the way and actually had doors that shut to hide it. That may be overkill to close doors to hide the TV, but it looks like you could have a retractable shelf in your built in for the TV. Can you do without the loveseat in the room? I think the loveseat interrupts your flow into the room, both physicially and visually. Instead, how about moving the chaise where the loveseat is and maybe getting a nice upholstered swivel chair to put over on the fireplace side which could be turned to face the TV or the fireplace. It could be placed close to the couch and angled in so it doesn't block the fireplace. Or, if you aren't set on having a chaise, an upholstered swivel chair could be placed on either side of the couch-nothing too big. That would leave the entryway less blocked. I think that would made the room look larger. I really like to look into a room and see an unblocked expanse of floor all the way to the other end, if possible. With a chair on either side of the couch with a small table between each chair and the couch, you'd only lose one seat from what you have now. If you really want something to recline in, consider a smallish lazyboy for one of the side chairs. We love our leather lazyboys. Also, I would move the grouping as far back toward the breakfast nook as possible. I love the built ins, the fireplace and the glass doors out to the deck. It's going to be lovely when it's all furnished.

Post pics if you want help.

To me there is a good balance if you are looking at the shapes. However I do not particularly like a TV over the fireplace.