I use about 200 junkmail addresses when I am testing online services with registration.

There is a system for unique codes and a registry of their related products all over Europe.

I don't know if it is possible to make PVC transparent, but I would guess that's what it is.

ask couriers to leave packages in specific places

Around here, they drop the parcel in front of the door and then they run away like thieves.

Sometimes they ring, too. But they don't bother waiting.

when someone calls me and whatever it is suddenly works when I do it

Oh, I know that so well.

Usually I caress their screen then, like it was a pet, and say things like "that's my boy" :)

So what's the use of all the other functions when you cannot (or don't want to?) open the door?

What about Openlook? I guess it's still working.
https://sourceforge.net/projects/openlook/

when the button is pressed, allowing me to watch its audio and video stream live, and speak back to whoever is at the door.

I'm curious.

You want the video and speak back and all, but you don't want the ability to open the door for your visitor? Why not?

Don't be a fool either.

Of course I am going to do this to you, not to Disney etc. because I am way better at creating proof than you are.

And of course Disney etc. are going to do this to you and me, because they are even better at creating proof than you and me are.

That's how foolish this law is.

do their job and go home. That's what I try to do.

I feel like this is OK and it is not your real problem....

feeling entitled to order you around, even though they are not your supervisor.

...but this is.

Do not play along. Learn to not get ordered around. Tell them / teach them that they can play their games at somebody else, but not at you.

Take an electrical lock with good mechanical quality. No smartness inside the lock itself, just a + and - wire.

Then put the "smartness" inside the house, where it cannot be attacked.

A cheap keypad on the outside, so you can replace it every year without shedding a tear.