Add "While Pressed" option for buttons "Alt, Ctrl, Shift etc." to customize shortcuts

I tried to change Blender navigation shortcuts to 3dsmax's, but I faced the problem: In 3dsmax you press the Alt + Middle button to rotate the view, then you unpress Alt while the Middle button is pressed and you pan the view. So you always keep pressed Middle button, and press\unpress Alt to pan\rotate view. In Blender if I want to navigate with pan\rotate I need always press the Middle button, then press Alt+Middle Button, and then press the Middle button again, I can't keep the middle button pressed and only press\unpress Alt. Also, it becomes an issue when I do modeling fast - sometimes I press the middle button earlier then alt and it not change mode to rotating. It's not easy to describe this issue very clear. It's better to practically navigate in 3dsmax to feel the difference. I think adding "while pressed" kinda option for keys in keymap editing, could solve this problem and add more flexibility for customizing keys in Blender.