Though it's still too early to take too much from his #s; RJ's down behind the arc and at the rim this season, but he's improved from the line & midrange, his assist rate is up, his rebound rate is up, his turnover rate is down & his defense is up. All while being more physically drained due to the minutes he's seeing & the cramped schedule.
What's most important when developing young talent isn't how far from the end of their growth curves children are, but whether they are making progress along their development arcs, and RJ's doing that this season despite the 3ball clearly not yet being in his arsenal...plus it's not like there haven't been countless players who only learned to shoot 3s later in their careers, so it's not like RJ is running out of time to add it to his skillset if it doesn't materialize by the end of the season
If I was going to be critical of RJ it would be the way he has started to force things in some of the games where his shooting frustrated him, and his finishing at the rim thus far. Although the picture there is muddied by the crap spacing (which he contributes to). Since, on a proper team, he'd have a much easier time at the rim & his rates would probably be more inline with his peers, I feel like, rather than pointing to a lack of touch, this may be more of "if you can dodge a wrench" situation...where having to figure out how to finish through the crowds we're forcing him to face early in his career could make him a lot more comfortable & confident around the rim when he's seeing normal NBA-spacing *shrug*