I thought the chatter was from the single mass flywheel not isolating the vibrations from the engine. The issue is always there, it’s just the design of the dual mass quiets it down. Dual disk exaggerates it because of the added parts to rattle. Your description makes it sound like there is a ton of slop in the gears and they don’t mesh right. Which means it would be a problem with dual mass, solid disk, or dual disk.
I could have misunderstood your explanation as well
dual mass flywheel keeps gears meshed together by continuing the momentum/energy of the engine between combustions. there isnt slop, but all gears have backlash otherwise there would be extreme heat and wear issues. if you ever set up a rear end and check the lash of your pinion to ring gear, just by moving it with your hand .005 of back lash can be heard VERY clearly. so that chatter is from the few thousandths of an inch of backlash.
hence, gear roll over is much louder at low RPM because of the timing between each combustion, at higher RPM the engine is able to smoothly transmit power to the transmission and through the gear train which results in less gear noise.
you can put a single mass flywheel with a single disk clutch and it will do the same thing, this applies for all transmissions because they all have backlash set into the gears. its more pronounced on a G56 due to the aluminum housing
Dual-mass flywheels were developed to address the escalation of torque and power, especially at low revs.