I think this extended Masters format helped Sinner to play himself into a form. If he had to play every day on his comeback after more than 3 months out, he would probably run out of gas. He is having some blister on a foot I hear, but it doesn't seem to affect his movement.
I think his game is closest to Djokovic in the terms of variety (the lack of it) and how comfortable he feels on the baseline. Young Novak was also reluctant to move forward. They have similar style of hitting the ball very early (on the rise). Not as flexible/athletic as Novak, but I would say Sinner is the prototype of a modern tennis player. Tall guy, with huge power who can consistently hit from both wings. Nothing flashy, but he is playing percentages the best at the moment. Very calculated from the baseline, but when he smells the opportunity he goes for it. I still think he lacks variety of Carlos to be a top player on clay, adding slices, net approaches and dropshots on clay helps a lot to overall game.