The larger throttle body will definitely make things more sensitive since 75mm is larger than the engine really needs. You have 2.25 the area of the original TB, so you've basically moved all of the previous area change into the first 40% of your pedal travel.
You could tune the opening speed by changing the cam on the throttle body, but you'd have to do some work to figure out options that match throttle shaft diameter and what their radius curves look like. You could just go completely custom and get the exact curve you want, but that comes with added work and expense.