I think they look wonderful in houses that are about 100 yrs old, and are enormous. Don't care for then in modern houses. Just my personal preference...

They will cost a fortune to paint.

In the plan above there are too many sizes and proportions of coffers to be attractive and the donut hole in the center will be a "what's that?" competition for the coffers. Given the diagonal walls, the random size coffers, the donut hole and the diverse linkage of shapes, you may want to consider simplification. Less can be more! :-)

What is the style of your house? I agree with Virgil that it may be too much.

I had wanted a coffered living room ceiling and try as I might I wasn't able to create one that would work in my space. Sometimes it's just not feasible.

To get the super thick coffers that I like, I think you need at least a 10' ceiling. Otherwise, I feel like they can't "breathe!" Those flatter ones can work, but they aren't the same effect.

It turns out the best if the horizontal elements of the "coffering" work with the vertical elements of the walls. In a remodeling it may be overly difficult to achieve.

What is that round thing?

I love coffered ceilings. But I feel like they either need to be even, or way far off in a unique pattern. I don't like how your pattern is very close but not repeating sizes. I'm battling coffers myself in my design, I'm too OCD and want them to line up with everything on the walls and all the windows (which would be great) but is a challenge. You usually have to figure out what the main focal point is in the room and have the coffers centered one way or another on that (fireplace, window system, whatever "it" is).

I'd try to go with a consistent pattern, try some different sizes and see if anything feels right. Not every room can handle them, so you might have to substitute for a patterned ceiling or something.

I don't think 9' is too low to coffer, but it can be. I think coffers make the room feel cozy, so I like them for sitting rooms and where you don't get a lot of foot traffic (if the ceiling is <=10'). That's my opinion

The planetarium? A blow hole? The chimney!

I am thinking it is a seating area off a counter top... But I'm dying to know what that round thing actually is also!! OP, please tell us!!!

I want to know what anyone needs with 14 burners on 2 separate cooktops

I would post your kitchen on the kitchen forum. Right now your island is a barrier that will make cooking more difficult

We're still dying of curiosity about that circular object in your hours plans...

What kind of nook?

It looks to me like the big triangle is an island with a raised element, then the solid circle is a build-in island/table? Chairs are drawn around it... The dashed lines (double tray ceiling) just make it look really busy on this drawing and hard to see

The island / circle table is kind of a weird combo, I'd have to see how it's intended to be used but it looks like a challenge

If you are redoing, I would highly recommend you vet your kitchen plan in the kitchen forum.

If you keep the kitchen plan as it is shown, invest in the best pair of running shoes you can find for the cook.

As I said post your plan in the kitchen forum and let them help you. They know their stuff. Right now your island is a barrier.

A round element and irregular shapes can be incorporated in coffering.

Yup, with enough money, and some skilled workers, anything is possible...

Thanks for solving the cooktop mystery! And I was kinda hoping that the round element was a funky bar.