sggolf Just did some checking on this driver and found out that 'tour' length is only 44.5" & Rickie Fowler plays his at 43.5, & 'stock' is 45.25(without CONNECT). That, of course(tour), is with different weighting, but still makes me wonder if 43.5-44.5 might be a better length choice for your nephew.
If the kid has no ego problem, others teasing him about generic/cheap shafts, I would think he would like the color ,and results, of the DTG FGS Electric shaft. It would give his dad a break for when he has to buy another shaft down the road.
I remember setting my grandson up with a similar set up when he was around this age. And he was skinnyassed, and not as tall. I did go 43.5 with his. The heavier set up is not going to hurt. (not sure what that head weighs, but thinking it to be 203+)