The talent level and impact ability are all there for Jost. He's one of the most talented players on the team. If you compare him to another tweener type in Andrighetto, Jost is more talented, has better puck skills when stick handling, has a better shot, better passing ability, and better vision. He just doesn't have Ghetto's wheels.
The only thing keeping Jost from displaying his talent regularly is his acceleration. Though he's been better in this area I think the last week or two. If he manages to keep improving that acceleration, you're going to start seeing him execute a lot more plays, and showing off that talent a lot more than he's not right now.
All the times he looks to make plays but gets closed off on in the O zone, all the times the defender knocks him off the puck, all the times he's turned the puck over in the neutral zone, all the times the passes haven't quite connected, all the times he hasn't quite found himself in the best scoring areas on the ice, all the times the rebound just missed him in the scoring area, are direct results of that core skating issue.
He's not creating enough space for himself to make plays when he has the puck, and he's not in the spots on the ice where the puck is going to be when he's waiting to receive passes.
If he can't continue to improve his acceleration he'll probably spend his career as a tweener type that leaves you a little disappointed. If he can though, I think he'll be a really good 2nd liner, and I'm not writing off his center ability either. As long as he can skate well, and has some talented help on his line, he has the tools to play that role as well.