So, here's my background: printing and publishing. I studied to make books, worked in printing houses, newspapers, before I turned into a programmer. But that was after I managed to land a "proper" job. Before then, I worked a lot of crappy jobs, including in the kitchen.
I'm not a chef by any means, all I'd do in my kitchen jobs would be the boring stuff, like chopping something or frying etc. In my work in the bakery I probably made couple dozens of thousands of doughnuts, but it's not the same as baking them at home, of course. So, it doesn't help with recipes that are normally designed for home-cooking.
But, do professional chefs use cookbooks? -- I know the answer to this one. No, they don't. Or, not in the way they are intended. I knew that some would use the books for inspiration for presentation (i.e. how to style a dish), but not for the ingredients or the cooking methods. Sometimes it's just a general idea, but never the instructions or the ingredients list. I.e. someone who trained to be a pastry chef doesn't need a list of ingredients to make, eg. puff-pastry dough. But there are plenty of variations of puff-pastry and similar doughs (eg. filo). So, a book may give a general direction by saying that this or the other particular pastry traditionally uses lemon juice. And the chef would know how to ration it and how to work the dough. The book cannot help with the later aspect, because that, just like any craft requires seeing / working under a master who'd explain how it works.
Most of the work of the chef has nothing to do with knowing ingredients or temperatures: the typical stuff that goes into recipes, the stuff you'd find in a cookbook. It's about knowing how to tell if the condition for cooking something is right. Take, another example: making the staple bread of the Middle East, the pitas. Knowing ingredients or temperatures won't help you make a pita have a pocket. There's no instruction that can explain what thickness of the dough do you need to make it work, because that's contingent on the hydration of the dough, the temperature of the oven / pan you use to bake it etc. But, even that isn't enough: you need to know how to kneed the dough, how to tell when it's sufficiently proofed, and this will depend on a lot of factors in your environment (temperature, humidity, age of the yeast, age of the flour, water acidity etc.) that are just not possible to capture well in a book.
> convection function
That's just not applicable to baking bread / pastry... Not even vegetables really. Maybe will work for something like a stew, or some other potted dishes, where it doesn't really matter how heat is distributed anyways. This isn't a function that I'd use in home-baking (I don't really make stews). And industrial settings are a different story.