I don't think it's a balanced recoil system, rather a custom-tuned gas system (plus probably a rubberised recoil buffer added to end of the recoil spring thing) that is optimised for minimum push required for effectively cycling that AK, notice how ;slap; from cycling bolt carrier is so minimal on this,
also that's a (relatively) heavier build of an AK form milled receiver so extra mass of the rifle could be helpful in controlling recoil-muzzle climb etc,
plus there's a big muzzle brake there - also good for controlling recoil,
finally it seems he's using a binary trigger i.e. a trigger that fires when trigger is pulled as well as released, needs some practice to master though,
and of course he's gotten a verticle grip plus his standing stance is wide enough to spread and absorb that recoil etc,
last but not least, he's firing a light recoiling round that 5.56 NATO is, what else to say...
...
combining it all together with the kind of training these competition shooter goes we get to see this sort of cool show of firing,
however getting such a mumbo jumbo thing for armed forces is quite...far fetched thing due to various reasons
