Pickles, this is what I have been trying to explain for sometime, I had this problem before the tune and after the tune it's still there but not as before.
The jerkiness, boost coming in and out with no change in pedal input, I even tried driving with manual shifting, but still the same.
If I go for a quick acceleration it will pick up quick and then have that pause and continues on, it's as if Its not comfortable with small pedal inputs, it wants you to floor it all the time.
But it's weird that you got it after the tune!