I use this AuthHotKey script to pan when clicking both buttons together (actuall, in the AuthHotKey script you have to hit right slightly before left, but it’s easy, and then its awesome). one handed panning.
It would also be great to have mousebutton+key shortcuts.
Thanks
AuthHotKey script:
#IfWinActive ahk_exe Rhino.exe
~RButton & LButton::
Send {Shift Down}
KeyWait, LButton
Send {Shift Up}
return
#IfWinActive