We had ceilings that were a little less than 8 ft in our last house and used 6" recessed cans. We also used them throughout this house, which has 9 ft ceilings downstairs, but 8 ft ceilings upstairs. They have the white trim rings, so blend with the ceilings and I think they're fine. I don't know if it helps, but here are photos that show the ones in our bedroom and in the fridge/pantry alcove of our kitchen, which both have ceilings at 8 ft. The one in the kitchen shows up more because of the green ceiling, and the camera captures a glow that makes it look more obvious than it does in person.

Green Designs says: The added expense of HVAC temperature control and stratified temperature layers is another. I appreciate your green focus, but this statement doesn't ring true, with me. Relatively small home (2400 sq ft, on my lot, was all that was allowed, but really pushes the boundaries of "open concept", with windows everywhere)- 10' down and 9' up. None of it energy inefficient. Quite literally, our energy costs are much less than many apartments with 8'-9' ceilings, and yes! It's all due to a well-designed home, HVAC system that's zoned and an energy-efficient temp control system. But I do know how on-top-of it one must be, to make the HVAC system good, before walls are put in. Hardest thing I ever had to learn. And? People hate ceiling fans and then design homes that require them. Then they don't own a ladder tall enough to change the light bulbs. First, not all people hate ceiling fans.They are there for a reason. I certainly don't. I bought gorgeous stainless- but no bulbs. That is a feature I don't like. But down- 10'- they serve to bring the ceilings "down", and they are part of our energy-conserving plan. Not hard to clean, and I'm 5'2". Just have the right telescoping equipment. Up: 9', still fans. And all those fans work together to prevent stagnant air. They also work well with the simple concept of a thermal chimney. As a result, we have very, very low utility bills. Quite honestly, we pay less than people with homes half our size/ One thing we really agree on is the need for great design. My architect lit the way. Another? Sure. Cabinetry can cost a bit more. I have cabs in the kitchen that go all the way up. But the upper cabs are storage, for seasonal etc, and complete the clean lines I was going for. No need for extraneous furniture that I really didn't want- currently in a minimalist phase. But planned correctly? The relatively small charge for the cabs, all the way up, cost me far less than whatever the heck I would have needed to store it all, and keep the look of the house. And well- they are so much easier to clean- no dust on top.

If you look closely at the photos of the fixtures, you will see that the Nora Cobalt is a "retrofit" type fixture (like the Halo the OP originally asked about) where the driver, heatsink and LED board are in one compact "trim" unit that is installed in a standard metal housing used for various kinds of fixtures. If the fixture fails, the "trim" unit would need to be replaced. The Lightolier LyteCaster L3 is a modular design with the driver (step-down transformer and current stabilizer) mounted in the housing and the light unit and heat sink fits into the "trim". If the fixture fails or the color dims, the appropriate part can be replaced. The parts can also be upgraded. These fixtures need a more substantial heat sink because the COB chips are more compact than the typical SMD chips. The Nora Cobalt is intended for residential use and the Lightolier LyteCaster L3 is intended for residential and light commercial use. I recommended them because they are both more powerful than typical LED recessed fixtures, are more deeply recessed, have an adjustable beam angle and use a superior COB LED. The L3 also has a great wall-washer for a more uniform light on a wall but it costs another $20+. There are no bargains in good lighting.

If all your lights are on dimmers, there is no need to reduce the number. Looks to me like you generally have all areas covered. If you want to go into great detail with a lighting plan, there are actually lighting designers who can work with you on that. Layers of light are what they would do with lights in different places and on different levels so that there are no dead spots. What you have here is simply overhead lighting. There is also under-cabinet lighting, under-counter lighting, stair lighting, and so on.