Working on slightly bigger level is hard, the movement speed in the viewport doesn’t scale with the scale of bigger levels, it is very slow. Both the mouse scroll “zoom out-in” and the keyboard (wasd) navigation keys,needs to be affected . A simple movement speed selection setting in the viewport… or dedicated keyboard shortcuts.
In Unreal Engine the problem is solved by hold the Right Mouse Button and scroll the Mouse Wheel up or down to dynamically scale viewport the speed.