I also have a FUT scar from 4 months ago which I've largely ignored. However, since I regularly do micrineedling over the thinning crown (no work was done with the transplant), I did consider moving lower down to the scar to reduce its appearance. Needling is indeed known for scar reduction, and yes it'll make micro 'holes' which are supposed to recover quickly, and shedding dead skin and generate collagen in the healing process, hence eventually making your skin look more even.
At the moment i still feel the occasional itch around the scar, so im leaving it for a bit longer before consider needling over it. I'm really not bothered as I wear my hair long anyway