It covers a quarter of my working viewport (and yes, I want to keep the viewport small) and consequently, most of the objects, so that often I have to work ways to select more objects that are near, because it hits the gizmo when I click!
You’re using the most-intrusive manipulator, the combined one.
I generally just have my fingers near the QWERTY buttons and if a manipulator is in the way, select another type that is less intrusive, like the “T” transform one.
Or you can just press F and reframe, zoom a bit, grab who you want, back out, etc.
The more time you spend actively moving the UI around as you use it, the more it will become second nature to not be static.
I use 3DS Max since 20 years, and Unity from about so long… I am used to the QWERTY input, but I just prefer the unified manipulator and have all in one place, but thank you for the effort.