Hi all. After several trial&error tests, I've found that the main problem is the
monitor orientation. While in the
Rafal Youtube's demo video shows that his monitor is in portrait mode -hence he doesn't needs to rotate the emulation-, mine is in landscape mode and rotated 270ยบ all emulation software.
After change the monitor to portrait mode in Windows and set rotation to 0 in all emulation software, tables are shown in VPX with headtracking at *
almost* all screen, so it still left a few centimeters to fit the whole screen. It's more playable but still there is some room to improvement (and yes, I've tried debug mode with F6 but it doesn't work with headtracking tables)

Hope it helps while still researching to how to make the VPX headtracking fit as good as BAM Future Pinball. Cheers.