What the guy in the video neglected to say is, when a blend door is broken, the controls (i.e. damper motor) will cause a damper door actuator to 'hunt' for minutes going back/fourth ...struggling to find either full open or full closed. That's how it calibrates it's position under normal conditions. Once it's calibrated it then knows where 20% open is, or 60% open, so it can be at the position the control logic says it should be, for optimal operation.
However, when a door hinge is broken it may not be able to find either end of open/closed (because the door shaft is broken) ..the damper motor may continue to 'hunt', even after you shut the vehicle off ...for a proscribed amount of time until it just 'gives up' as determined by the number of attempts the programmers put in the logic. At least for a few minutes if not several minutes. When yer driving the car, a person may sometimes hear a bunch of 'creaking' where the controller is trying to determine full open or full closed and it can't (again, if a damper door hinge or shaft is damaged). It may go on and on, maybe stop ...and after a while it may try again. Like I say, it can be annoying as all get-out if it squeaks a little and things like that bug ya. That's reason enough to replace the doors if you plan to keep that ole girl!!
And the other thing is, if an indoor/outdoor damper is broken, or becomes broken/damaged, you could get full outdoor air in the winter time, meaning if a guy lives in northern climates, it can allow sub-zero air to stream in all over your little lady's bare legs. The HVAC system cannot even compete with that, so it'll be a very cold ride under those conditions. Been there.
Just sayin'. And if a mode door is broken (different door than the inside/outside door), the defrost may not work in the winter and it could lead to all sorts of wonky HVAC behavior. This kind of stuff is similar to what also sometimes occurs on other various makes of vehicles with sophisticated HVAC systems. Blend door breakage is somewhat fairly common across the industry when cars get some age on them. They ought to make those damper doors 100% bullet-proof so they don't break! It would only take probably 50 cents more effort to make more durable hinges, even if they were made out of plastic.
Overall, I love the idea you're changing the interior to a nice upgraded level. It's going to look nice. Did you buy it all removed, or get it from a salvage yard? How much did you pay, if I can ask? Show us the before/after shots if you have them.