Ok. Atleast we know the Maf is not the issue so we can try other free checks first before splashing out on parts.
What is the condition of the induction pipe itself? (The rubber corrugated pipe that attaches between throttle body and the plastic pipe leading down to the air filter).
Remove it, seal the ends with rubber gloves and elastic bands so it's air tight and test it in a bucket of water to check for any small splits where air bubbles escape from. This is a weak link on V6's and can result in bad running symptoms that you have described. When demand is needed at high throttle, a leak will cause the car to run very lean so you get flat spots and won't throw up a fault. The maf has done its job already by measuring the right amount of air flow but a leak further up will let a lot more through which upsets all the rest of the sensors and fuel measurements etc.
Thus the bad running.
They are expensive from a dealer so most owners usually tape up leaks or replace them with silicon pipes instead, like me
Next is a throttle body clean... Plenty tutorials on how to do it properly. Then perform a throttle reset procedure. All easy to do and more importantly, free.
Another question... When was the air filter itself last changed? If it's been over 12,000 mile or more than a year, time to replace as they can also get chuffed up and affect full throttle behavior
It's a common misconception that V6's are sensitive.... Trust me, they want to run right and will do so for as long as they can , so it will become obvious if something is preventing it from doing just that....
Do the easy stuff first, you never know, it may be obvious and simple to rectify. Then get any fault codes read just in case. A mobile app like Torque pro and a bluetooth elm327 adapter odb plug is all you need, this will soon tell you if something isn't well with the rest of the multitude of sensors etc.
Bring back Tapatalk !!!