I don't think that's fuel cut at that boost level (around 0.9bar), but it depends how far over that line it's going (could you estimate?). It's most probably the coilpacks as previously suggested.
This may be a red herring, but bear with me.... Until recently my MY95 WRX was hitting what appeared to be fuel cut in 2nd and third gears at high boost (1.1 bar with an ESL chip). I replaced the alternator last week, to solve a voltage issue that I was having and now the car doesn't appear to hit fuel cut any more..... Now.. The weather has been milder (so boost has decreased a smidgen), but I have a thoery.... If the voltage to the ECU wasn't sufficient or fluctuating with the old alternator, it's possible that sensor readings etc. were not being read correctly, so it "thought" it was overboosting. By replacing the alternator the voltage is now correct, so all the readings are correct, so no fuel cut. This hypothesis may be complete donkey's gonads, but who knows, it's another possible solution...?