Hi, keyboard controls to always be able to scroll these kind of windows throughout [CGMZ] plugins will be added tonight with the monthly [CGMZ] Core update to version 1.25.0. The update will add keyboard keys that you can always scroll with + allowing mouse wheel to always scroll the windows (in addition to gamepad+touch screen which can always scroll already, but it sounds like you have disabled touch screen).
Selecting things to manually scroll was removed because it was causing a lot of user confusion, where they would hit enter and not realize it activated the window to scroll and instead thought it froze the game.