Although body hair transplant is based off Follicular Unit Extraction, it is not exactly the same. Taking grafts from the areas of the body needs to be done with more advanced punch tools compared to regular FUE surgery. Features of these instruments would need to include the following.
(1) a gentle pulling mechanism which separates the follicle from the surrounding tissue
(2) punch edges which create wounds with minimal extraneous tissue
Follicles on body areas such as: legs, arms, chest and face grow at very narrow angles, close to the skin. This is very different from head hair where the angles are often closer to ninety degrees.
With sharper angles, a punch edge is likely to damage the hair follicle. Therefore, the goal should simply be to separate the grafts from the tissue, not just to rely only on the punch.
BHT tools would also need to ensure excellent wound healing without visible scarring on the donor regions.