A more efficient light. Means less energy lost as heat.
This is true. Except in practice, there is not a huge difference in efficiency between top-tier lights so heatsink demands don't change that much. The main reason HLG gets away with it is surface area of the mounting plate. They use quite a large aluminium plate to mount the LED panels to. The side reflectors add to the surface area, acting like heat fins.
I never liked the idea of mounting the driver to the same heatsink, but if you can mount it on brackets where it doesn't come in contact with the main heatsink, then that is better. Heatsinks work both ways: they remove heat from LEDs but they also add heat from drivers.
What
@Rocket Soul was trying to explain – because you're both on the same page – is that lower Vf bins can be more efficient, which means they produce less heat.
But again, in reality, the lowest Vf bins are not always the most efficient, as it is entirely dependent on what Flux bin they fall into. There are very, very few LEDs that are both low Vf and high flux. In theory, these would be the most efficient, but in reality, the lower Vf bins also tend to be the lower Flux bins, which means that LEDs within the same family mostly run at similar efficiencies with a few outliers in the higher and lower efficiency range. If you have access to these high efficiency bins (because they are only a fraction of the production total), then you can build a more efficient LED panel.
But even then, there is an argument for running a bigger heatsink, as better heatsinking leads to better LED efficiency.
horticulturelightinggroup.com
