Can FUE Extract Beard Hairs Without Leaving Noticeable Scars?

Yes, FUE extraction of beard hair is a very viable option for most patients that need to expand their donor area. Typically, the scaring is not cosmetically significant when the healing is complete. In some patients white dots are a possibility, especially in darker skin tones.
Beard hair use is great for those whose head donor source is depleted, either due to advanced male pattern baldness or prior botched surgeries.
For an example of a NW 7 patient with darker skin tone who received beard to head transplantation watch the video or use the link below.

It depends upon the color of the hair and skin.  It is possible you can end up with white dots on your skin.

Generally and surprisingly, beard donor hair does not leave visible scars in light skinned individuals, however, in darker skinned individuals, the small white dots from healing can be seen.