Now, with the Unreal Engine and its physics I would like to request a better, more accurate aiming for underbarrel grenade launchers, because the present situation is almost like having no sights at all. And not just an ordinary direct fire 50-350m distance-adjustable sights, but the new type of sights with incorporated additional feature - indirect fire - to enable reasonably accurate indirect fire - launching explosive/smoke shells in high-arcing ballistic trajectories enabled by the Unreal engine. Exactly like mortars do. It is possible to use indirect fire in game even right now, but there is no way to aim at all and no chance of target hit. See for example the TechSolution's M203 Grenade Launcher Indirect Fire Sight (IFS) for details.
To take a page from real life, the easiest way to fix this is to add a ladder sight to the top of the foregrip.
This lets one use the front sight and ladder together to judge distance.
The sextant sight on the side of the foregrip is an elevation-adjustable precision aiming device for grenades, if it's not able to be "sighted in" and adjusted for distance, then it's literally worse than no sight at all, since it blocks vision of the target.
It would honestly be better to simply aim down the weapon sights and guess, rather than holding the gun at port arms and blocking any chance to actually see what I'm shooting at.
I'd prefer a leaf sight over the quadrant sight currently ingame. What they should add (in my opinion) is the ability to use the mouse scroll wheel while aiming down the sight to either rotate the quadrant sight or better still change the alignment of a leaf sight for distance. Been wanting this since Ins2014 but nobody seemed to care as much as I.