A flickering check engine light with a rough idle on a Superb III is usually a live misfire, not a stored fault.
Here are the likely causes, what to check first, and whether you can keep driving.
Why the light flickers instead of staying on
If your Superb III has a check engine light that blinks or flickers while the idle stumbles, treat it as a live misfire warning rather than a stored fault. On the MQB-platform Superb (2015 onwards), the ECU cuts fuel to a cylinder it sees misfiring and flashes the light to tell you that unburnt fuel is being pushed into the exhaust. That fuel then burns inside the catalytic converter, and converters do not survive that for long. So the flicker is the car saying: this is happening right now, not last week.
