Team momentum does not affect you at all when you are in full control. It only affects the simulation portion in between the parts you control.
That being said I do notice the AI changes (not just on Dynamic) between games, especially in the playoffs if the opponent has not won a game yet. I've had games where the batters suddenly turn into HOF hitting, nailing wall shots off sinkers 5 inches below the zone. And I've had relievers in red tiredness paint the corners over and over against me. Then if I lose the next game deGrom ends up grooving changeups down the middle and I win by double digits. It's just a quirky mode in the playoffs.