I think Jaylen will be fine. He is playing in SL where the ball movement is not crisp, lack of an open court to get out on the break and be a finisher rather than a creator of his own shot, and is most likely focusing on areas of improvement (ball handling, passing, shooting the open three pointer) rather than solidifying his strengths (finishing in the paint, open transition buckets, defense)
Once he's back with the A team, he will not be doubled in half-court, will have easier opportunities on the offensive end to score and his weak areas especially with ball handling will be masked by the IT's and Smarts of the world who will run the offense and get Brown the ball in places where he can finish.
Brown will be fine in the long run.