You can resize the manipulator in blender too, though I don’t beleive there is a shortcut for it.
All of the options interrupt the workflow somewhat. A modifier key changes the standard for selection, and there is no spare modifier key to use in this instance. Using a different control to perform the same action when the context is only minorly changed is typically something to avoid.
2.8 doesn’t solve the issue, if the move tool is up, currently you still cannot click through, and the manipulator cannot be hidden by hotkey short of switching tool.
As I said before, the separated workflow is also about removing ambiguity. You know you can’t misclick, so you don’t need an extra keypress or modifier and you can be fairly inaccurate/fast with the mouse.
The point is, the separated workflow doesn’t encounter the issue at all. This is a benefit.
On a different topic, has anyone else noticed that the new spacebar tool menu doesn’t disappear when you move your mouse away? This seems odd.