Well i've seen two sides of that coin, that JR is overrated, and then that JR is overlooked as you say.
I personally feel, that having JR does significantly increase your 3pt % as well as mid js %, of course you don't have a category for mid jump shots on the stat sheet, but in game on the floor whever they do shoot is part affected by JR, I believe.
So I will train JR a little sooner, possibly next season, but this season, I'll focus on JS and OD.