I want to use wtype for pasting the content of my clipboard. I want to use Shift+Insert (instead of Ctrl+V or Ctrl+Shift+V) as in my experience it works in more places.

I tried wtype -P Shift_L -k Insert -p Shift_L and wtype -M shift -k Insert -m shift and they both work in most places but neither works in Firefox address bar. Manual Shift+Insert does work. Also Ctrl-Shift-V via wtype works there. But not Shift+insert via wtype.

Is this an issue with wtype or perhaps Firefox?