The following is about the task to get a smooth and controlled drive. It is not the wish to "transform" her into a race car, she will keep what she is. The tries are more or less a fun on it's own.
Intermediate state. First pic shows the first attempt to move the MAF sensor. The result is good with regards to the thottle response with better dosage and less throttle way. High rev power is with more ease but low rev torque is unfortunately worse than with standard tube.

I removed a plastic tube inside the MAF sensor tube of the Focus part...out of curiosity and to learn how much influence edges may have due to unwanted turbulences.
This inside the Ford part second tube eliminates sharp edges, and the effect of removing it was very significant towards the worse. Lesson learned, and I avoid sharp edges whereever possible. Because we work with cheap and several parts we have to make links between aluminum tubes and silicon hoses...producing sharp edges. Of cours the Ford Focus inner plastic tube was replaced and we rounded all the edges of our aluminum tubes. Important seems to be the additional aluminum tube inside the silicon hose which is mounted to the TB.

after treatment:

Also the ali links between hoses got smoothed.

After a first ride with the smoothed tubes inside the hoses the results are very promising also with regards to the low rev torque. As I don't want to make more than one change at a time the results are even very good now, keeping the original airbox, The only alteration: The airbox is feed with cold air from the down section front of the car since a year.