Personally I’d prefer them not to spend much time testing fin configurations for cooling. It’s just an added cost, I want a cheap well built host.
Just look at a heat sink that is designed to be used without a fan, they’ve been engineered to death . Kiriba-ru is a smart guy, have a look at what he made for Convoy C8’s.
Deep thin slots make it hard for air to move, once the air gets hot it needs to move out of the slot and be replaced by cool air. Wider slots are also faster to manufacture, there are less of them to make and a wider tool is stronger. Less chattering and more coolant flushing chips out leads to much faster feed rates. More parts per hour, less broken tools and less scrapped parts. It should be easy to talk the manufacturer into it as long as the end result looks nice enough to sell. Kiriba’s design will look good to knowledgeable people, probably needs to be tempered some to make it look good to the masses.
Their existing design isn’t bad compared to most lights and could be kept if need be. Just keep in mind deepening the existing slots won’t help much in cooling but will increase manufacturing time, break more tools and scrap more parts when the tool breaks. Adding your tapered section will help spread heat across the head of the light, might be almost as effective as the best finning. I’d prefer a stepped design. Its probably faster to machine and could be used to install a shelf for multi emitter optics. Either way its less material for the manufacturer to remove, less time equals cheaper to manufacture. They just need to spend a little more time making sure the reflector fits, shouldn’t be a hard sell.