Hi
First question, do you have an engine management light on?
Second question, have you had the car scanned for any codes?
Usually only 3 things can cause a misfire, spark, fuel or compression.
If the misfire is apparent at idle try lifting each coil pack up and see the difference, if you have a faulty coil when lifting it off the plug there will be no difference in engine running.
If you find a suspect coil, swop it for a known good and see if the issue moves cylinder (this rules out valve issues)
You mentioned replacement plugs, it is not unknown for new plugs to be faulty, or was the issue apparent before the plug change.
The MXR 2.0 engine has VVT (variable valve timing) and this uses oil pressure to operate correctly. the rev range would indicate VVT initialisation depending on throttle position and load, are you sure the garage used the correct oil for your car?
I would suggest purchasing a OBD scanner, this will show you any stored codes and if you use software such as Torque Pro or similar you will be able to see engine operation parameters in real time which will assist in narrowing down the problem,
I think we need more information to be able to diagnose.
Good Luck