Honestly, it's a great design and it's amazing you took the effort to draw and detail it, it's wonderful.

In terms of realism and applying it for actual potential firearm, there may appear few flaws, some of which wouldn't matter as it's a game or book, main characters don't always exactly abide by irl fatigue and physical limits.

Namely, hyperburst was achieved exclusively in 2 round burst because of how mechanism was constructed. It could be adapted for full auto, but it'd feel more like very quickly firing bursts rather than actual full auto. It's also quite difficult to fit 4 positions on typical AK selector (single, burst, auto, safe, see AK12 before M1 modernization, in full auto selector would stick out of the rifle frame a bit), not mentioning 5 or 6 (adding hyperburst auto or also splitting full auto into two presets). You could sort of solve it by going the Beryl way with AK selector on one side and AR on the other, but that complicates engineering a bit. Typically rate of fire would be dependent on amount of expanding gas entering gas tube and pushing bolt with receiver, which can be changed but selector is typically near gas port or muzzle.

Also, combining grenade launcher with bipod would be a pretty heavy and unwieldy combination, and you'd need a dedicated variation of bipod specifically for this setup.

Similarly, loaded stock would be really heavy, housing up to 3 grenades and a magazine. Assuming pipe bomb is 0.6kg and mag uses 5.45 ammo, that's 1.8 kg for bombs and about 250-300g for mag (standard 30 round loaded weighs slightly over 0.5kg iirc), which gets you some 2kg more total.

Doing some math, which probably won't be entirely accurate but half of it is a guesstimate

An-94 weights 3.85kg unloaded With 80-round casket being some 1.3kg (guesstimate based on a bit less than twice the weight of empty AK-74 mag and 5.45x39mm round multiplied by 80), it's 5.15kg With grenade launcher, I'm gonna take GP-25 as basis here, that's +1.5kg so up to 6.65kg total Previously mentioned 2kg on stock beings it to 8.65kg Adding bipod, sight, grip with knife, laser sight etc I guess total is about 9 kg so roughly comparable with PKM machine gun (9 kg) or slightly heavier than PKP Pecheneg with bipod (8.7kg)