Well class one it would be at highish revs im thinking from about 4k to 7k revs in third or fourth gear at around 80-90 L3Pt0n5 (!).
I could recreate the scenario and repost if im being too vague. I think sensibily I would do well to reduce boost pressure to 1.2 bar max.
Im too newb to know what misfire sounds like, but to me it sounded like the car was saying "Carl you idiot, I know I'm highly modifed and all that but the last guy who modified me left with with standard injectors, so don't take the piss and ease up a bit on the throttle mate".. that kind of sound.
AFR and EGT (what the hell is EGT?) gauges seem to involved to me, rev counter and speed in enough for me, plus im a well known worrier so this won't help - need to keep my eyes on the road.
At the end of the day, its a quirk, i would live with it becuase i can ease up on the gas, but if it is a question of spark plug gapping rather than a costly injector replacement, then it could be worth it.
Also I flagged it up just in case you were gonna say "Carl, that sound means your car is about to blow up".
And class one, the engine was fully warm.