I have Fr, but in German, and I tried to figure something out, but it's not easy... As for vcds, I know that it's a bad logger, very small sampling, I always use ME7logger for the old ME7 and there is a difference.
Please, can you give me some advice from your experience as to where to look? Because from what I see, you are a specialist and you have probably done stage 3 in this controller more than once, and my tuner says that it cannot be done more, but on the other hand, the person who modified the turbocharger says that you can easily push the top 1.1 to 1.2 bar. Maybe you'll save me from uploading the firmware 50 times or more.
Did you check link in my signature?
https://www.vehical.net/You can log it correctly, and you can get LIVE tuning for it, so you can make changes with the engine running (or load the sw in a few seconds).
And if you have the FR you can watch the flow charts and log every single parameter on the flowchart.