We should get him. He is not really a world class talent, but from what I saw from him, he can be better player for us than Dybala or even Berna in knock out games of C1.
For me, he has everything to be a knockout games's player. He has very good technique and great off-the-ball movement. He can shoot very well from both inside and outside the box, dribble out of defender with his technique and speed (which Dybala now can't do) to break the opponent's defensive line. And more important thing are his work rate. In C1's games, when all the teams are very well drilled, his constant off-the-ball movement is more effective than passively play-to-feet football (unless you are a young Messi).
Another advantage for him is his efficiency in using both of his feet. When oppenent's defender is really good, a two-footed player is generally much more effective than one-footed one, unless the one-footed one is too quick for defender to handle (Messi, Robben). Both Berna and Dybala are very one-footed player, they always need to take the ball to their left foot to dribble and even for pass, and since they are not quick enough, they are easily handled by relative fast and offensive defender like we saw in the Ajax, Atalanta games.
So even though Chiesa is not as talented as Dybala (for me), if we want to have a better chance in C1 next year, changing Dybala for Chiesa is not bad at all, and if we can add a extra good CM from Dybala's sale, it is no brainer.