the warm-up pitches before the inning starts. Not the actual pitches to the batter. They are giving 90 seconds to get nine pitches in. And while that's maybe enough time, the fact that there's a clock is going to force the pitcher during warm-ups in the back of his head to say, "I've got to get these in or else"- I just don't like that. If they would bump it up to even 100 seconds, I could deal with that.
But I did often wonder why they didn't start the games sooner. Heck, I would have actually started them at 8 AM in the morning, or use Rickwood Field for a game that looked to be the least attended.