I've had a similar problem.
Seemed at ~7K RPMs, the car would lose power for a bit. Seemed mostly before the car was actually warmed up.
On occasion, I would also receive a P300(random misfire) and P302(rear rotor misfire) code, only when in high RPMs.

I've replaced the coils/wires/plugs, no fix.
Cleaned MAF sensor, no fix.
Fuel pump replaced, no fix.
Actually changed the MAF sensor, and it cleared it up. Haven't gotten a single code since or noticeable power losses.
I didn't have any other symptoms of a bad MAF sensor.

Not sure if it will help, but just throwing my two cents in.

Or it just cleared up on its own, which is quite common, and you spent all that parts swapping money for nothing

You can't say it was the MAF when you clearly have no idea what you are doing