I have never come across a knock threshold while live emulation dialing in MTB via steady state testing at 9.5:1 sub 450bhp on the 1.8T, I cannot comment for 2.7T.

I have found the higher CR setups perform better than the same setups with lower CR.

Maybe on an old design engine the lower CR would have had to been a must to run higher boost, but the 1.8t 20v setup has a very good combustion chamber by design.

Look at a 2.0tfsi on stock ko4 30psi @ 3600rpm taking 18deg advance with zero knock at 9:1 due to combustion effichency.

Mapping plays a huge part, (did I read somewhere Prj tunes to knock, running lean the richening up on the onset of knock). Maybe it was someone else.  But if tuning this method then knock will be an issue on a higher boost/ CR setup.   Tune via knock prevention by management of the fuel and a hell of a lot more power can be extracted.

Oh, and since everyone is posting random things without any data to back it up, let's just post a graph from 30 psi on a 5v 1.8T with 9.0:1 CR and stock head at 30 psi, shall we?
Note how timing starts to get pulled due to knock before any boost actually builds in the engine.

First of all, no one said that they can't make 450 hp with stock pistons and stock CR.
They can, but if they'd drop CR on the exact same car on pump gas, they will make 500+, while gaining responsiveness throughout the revrange which has been my point all along.

No, I am not doing anything "wrong". This is how it is.
I posted a log to back this up, and this has been the same on every 9.0:1 with stock head.
If the head is modified it is a different story.

But since you are "all that", maybe you would like to say what exactly I am doing wrong based on that log?

And that will show absolutely nothing unless you take the same car, stack the head-gasket and re-tune it.

This was on small port head.
Full boost on that log is about 5000 RPM, the car is at 0.8 lambda from 4500 rpm. I am sorry if I don't immediately flood the car the moment someone goes near the throttle.
The ECU on that car was reading knock just fine, confirmed with detcans, as I always do on any engine with forged internals.
This car had no intervention whatsoever up top. The graphed timing is zwout. And if you care to look you can see that the spikes are at the points where timing is pulled from cylinders.

Oh and, if you do tune this, turn the meth injection off. As that is equivalent to running race fuel all the time.
My RS4 makes up to 10 deg more timing up top with meth injection. Obviously then 9.0:1 starts looking better than it is on pump gas.

A large port head still isn't magically going to win you 10 deg at 9.5:1 CR.
As I said, take a stock 1.8T 5V 9.0:1 engine, big port or small port and put 30 psi into it on pump gas, then see what timing figures you come up with.

Obviously you should be doing cams, head, and so on, but if you are not, then it is a different story.
The stock cams are also pretty brutal, don't forget that. If you are running cams with overlap, then in fact your dynamic compression ratio is lower, so you can not compare CR directly.

That does not sound right for pump fuel, and it's a pretty useless number without knowing more about the setup.
Also, I have serious doubts of that turbo making 30 psi at 6800 rpm, as if it did, you'd make much more than 430 bhp running that timing.
Sorry, your numbers don't match up. The log that I posted - the car made about 430 even with that crap timing (more exactly, 350 whp).

I use emulation as well, but an emulator is not needed at all on ME7 to adjust timing in real time on the dyno per load cell.

Talking pump gas:

1. No one ever stated high CR does not work, it was stated that lowering CR will allow you to extract more power.
2. You will not notice any difference driving the car until about 8.0:1, because down low throttle response is governed by pedal mapping more than anything on DBW cars, the difference in CR is not really noticeable.
3. With higher CR rpm vs boost will look better, but time vs boost and time vs RPM will look worse.
4. The factory runs high CR due to emissions and even the factory drops the CR on the K04 engines, although this is travesty from their standpoint of emissions.

Not an FSI motor.