Here are the directions I used to bake my wife's at home. Personally I would get my skates done at a shop for fear of messing them up, but since she was never going to pay for that I decided to do this for her. The process was easy and it worked pretty good.
When skates were made of leather breaking in was the same thing.
With composites, plastics, fiberglass the material resilience is much higher and requires heat for it to properly shape to the user's foot. The only part you break in is the padded lining inside the skate.
Still incorrect. A bake isn't breaking them in, it's fitting them to your feet properly.
Sorry, neither of you are completely correct, you both have correct parts haha.
Baking is necessary to achieve the right fit in certain circumstances, such as a properly fitting boot everywhere except for a hotspot or two on the ankles. A bake should alleviate that problem, but that doesn't necessarily mean the skate doesn't fit.
Baking would also be highly advised to do with certain skates that were designed to be baked, such as the CCM U+ CL or U+ Pro. Boots with composite outers (APX, T1) are also designed to be quite heat reactive as well.
In general, a bake is a means of minimizing the break in process/time.
It's not mandatory, but under certain scenarios it would be HIGHLY recommended.