Maybe add a tripod/bi pod/X pod that can attach to your weapon, meaning you can’t move when it’s deployed but you have + acuracy dependent on the terrain below or around you?
Sounds like fun. Deploy big machine gun in a window, RATATATATATATATATATATA~.
Turn those Zs into a fine red mist.
I seem to remember someone suggesting this earlier, the vibe that I ended up getting is that it would probably eventually go in, but maybe not for a while.
This could be implemented as a firing mode that immobilizes you and takes a while to enter and leave.