IMO, you'd be wasting your time on the dyno.
If the car is misfiring, the fuel is not burning and using up oxygen, there fore, whether 10 litres of fuel is going down each cylinder per cycle, the car will read lean unfortunately.
So, plugs have been changed, and coils have been changed.
There is still a LOT of other things that can be done.
Clean AFM for one.
Check the temperature sender that goes to the ECU (The dash may read fine, but it comes from a different sender)
Check the CAS too. It could be jumping around internally a bit as it accelerates.
If you bring it on boost in 5th gear, does it do it exactly the same as in 1st gear?
I'd also be checking all hose clamps, and EVERY air line (Not just intercooler, but all rubber ones too)