The main problem I found is the tracking and perspective that, starting the job, I thought as quite easy and possible. I'm using the Corner Pin effect and I've tried every single thing that came to my mind to actually make it perfectly tracked to the real phone but there are issues.
I even tried to track the four real corners of the screen and then link their positions to the corner pins in the Effects of the reconstructed HUD but somehow it gave me horrible results. The video shows my current situation: do you have any idea about how to make it stop trembling? I already had to correct the movements manually with dozens of keyframes.