Plastic latche for tool chest(box)

I think - finally - I will end with prototypes, and tune the the solution.

I have next question regarding the walls draft or taper of plastic chets

Most of them are drafted with min 2 deg. I made my first design also with drafts included.

However, I like the way DeWalt made it box system, and it looks like there are no drat, or at least it is less than 0.5 deg.

How did they achieved this? Is there any other reason to make drafts apart of molding requirements?