It's so interesting to watch an expert do their own car. Can you tell us the "why" as well?
I assume the why is regarding disassembly. The simple answer.. PPF is made to protect, not be noticed. That is why we follow this process among other steps before laying any film. The bumper, headlights, fender badges and vents are removed to make sure all panel edges are wrapped on the QV. If I was covering the whole doors, the mirrors would come out along with the door handles. I'm installing a track pack so that covers the lower doors and rockers. Along with mirror caps, A pillars, and portions of the rear bumper behind the wheels. I'll also cover the roof for peace of mind.
The disassembly also helps to limit concern for a customer who uses an automatic car wash and potentially lifting film. It also eliminates dirt collecting on the edge of the film and then becoming noticable. This is especially the case on light colored vehicles. Which then requires a visit back to the installer for a trim, I'm not a barber. 😉
We treat all vehicles the same, as if they were our own to make sure complete coverage is damn near achieved. We just finished up a full stealth (matte) PPF coverage on a new Audi E-Tron GT. I felt like it was my baby by the time we were done with the amount of time, work, and care spent on it.