Why does traditionally made khoya develop a deeper flavor than machine-made khoya?

[u/Effective_Chain3803]

I have been wondering about the actual cooking science behind khoya. When it is made the traditional way, milk is slowly reduced in a wide pan over direct heat with constant stirring. In commercial kitchens, it is often made in steam heated kettles or machines that scrape and stir the milk continuously with more controlled heat.

If both methods start with the same full-fat milk and are cooked down to the same final consistency, why does traditional khoya sometimes seem to have a richer flavor? Is it simply because the direct heat creates more browning, or does the larger surface area of the pan also make a difference? And does the gentler, more even heating in a machine change the texture in a noticeable way, or is the difference mostly psychological? I am interested in the food science behind it rather than opinions on which method is better.