I agree he has a say but I haven't ever seen the kind of communication from Dino I would expect if he was the primary play call guy. There was a noticeable change in the way plays were called when Sean Lewis left and Mike took over.
But I go to most of the games and rarely sit close enough to really see what is going on, so my vantage point is not the best.
That said, there were a lot more delays in calls late in the 2019 season, which I would expect if the HC was making more changes than he had previously. I do believe he became more actively involved in the last 3 or 4 games.