Hello!
After a week of driving it (~260 miles) the idle is now very stable, just as stock.
The power as greatly increased from 2000rpm through redline, it's really noticeable!
Below 2000rpm, it's different as expected. between 1300/1500 and 2000rpm, it feels like stock, and below that there's slightly less, but it's completely out of the operating range so it doesn't matter much.
I checked it everyday (we had a quite hot week this week) and no problem detected.
So, testing continue next week
and May 24th I'll do a trackday with it.
Ben