Does a smoker box do anything a dedicated smoker can't?

Factual Questions
1

I’m trying to determine whether someone needs both. Smoker is one of the vertical ones where you put a tray of wood chips and a tray of water, food on racks above, and it is lit with either propane burner on the bottom or electricity. Not a pellet, charcoal, etc. The box is reusable and filled with wood chips and placed near the heating of a propane or charcoal grill, with food off to the side for indirect heat.

Any reason why someone would want the box if they already have a smoker, besides being able to do two things at once?

Cold smoking perhaps if the smoker doesn’t go that low?

2

That’s the only thing I can think of. I want to try and smoke cheese when it’s cold out and I can’t get my smoker to go below about 125.