Even with my small hand (Mechanix glove XS-size user here), I can easily move my trigger finger between the rifle's trigger and the grenade launcher's trigger.
exactly although these type of grenades are still based around the High-Low Principle which means that it's trajectory is more indirect than that of a rifle. which is why I said Theory.
The sighting system as such is larger and based around either a latter sight like the M203 or in this case a graduated sight.
Critical here is getting the weapon to the right angle to drop the round on the target. So the User is going to look at the target and estimate the range they then will in a Latter sight line up their view of the front sight through the rear sight rungs that most closely match the distance to target. In a graduated sight They will adjust either the height of the slider ( Old Skool style) or the angle of the arm to where the sight sits for the angle to the range.
so the user will be making changes to the way they aim and shoulder for firing.
It should be noted that the Unit shown is not capable of being operated. Like most Underbarrel launchers the QLG series is not able to be fired independent of a Type 95 carbine, At least not with any chance of accuracy. the Carbine gives it the Stock and Pistol grip needed for support of the weapon.
This is a common issue for a number of underbarrel launchers only a small handful are true dual use ( either stand alone or under barrel) The M320/M320A1 or Canadian EAGLE for example can be mounted to the weapon or have a small stock attached and carried and used separately.
Looking at it structurally If the PLA wanted to They could likely follow what FN did with the FN40GL they created for the SCAR rifles, Or KAC for the M203 launcher and add a Stock chassis with pistol grip Or they could Follow what the Russians did with there GP30 And spin off a Stand alone unit based on the same barrel and mechanism but with a fully integrated pistol grip and stock.
Another point I want to make is that Grenade launchers like these are designed to extend the range of fire but at the sacrifice of explosive. a hand grenade thrown by hand will maybe make 35 Meters, but has an effective range of 10 Meters, A rifle grenade version of that same grenade might make 250 meters but with an effective range of only 100 meters a Grenade launcher can drop rounds out to 400 meters (and some newer rounds can make 800 meters and that's not mentioning the Pike missile which can cut out to 1.5 miles) and have a 350 Meter Effective range or better.
The round used here is a 35mm well most internationally use a 40x46mm or Russian 40mm VOG25( to correct a popular myth 37mm flare launchers are often used as stand in's for grenade launchers in TV and movies, as 40mm is limited and most makers will not sell to civilians with due to the NFA which classifies them as Destructive weapons. 37mm are smooth bore well 40mm are rifled.) it may be that the Chinese chose to go smaller in hopes of increasing range vs the Russian VOG25 and get ranges closer to the 40x46mm of NATO spec well sacrificing explosive.
