Yes, many times in my 67 years.
It is not so difficult as you make it sound (once you get past the plethora of connections, particularly related to the environmental controls). Additionally, I see Tesla selling this range extender as a spare power wall. You'd have to have at least one conventional one, and then this thing can be added for normal use around the house. If they're going to do that they're not going to have a technician come out to move it every time.
Also, the idea of them swapping it at the service center is not good. Where are they going to store all of them there? They could do a lease system, where people going on a trip could lease one for a month or whatever. That might be a reasonable business model. But, somehow they have to make a way for people to get it in and out of the truck in their own garages, if they hope to sell any at all.
I actually think separating the range into two pieces like this isn't such a terrible idea. Obviously we all would have liked the cheaper prices, better specs, that we expected. But we also got a lot of things we didn't expect. And, as far as truck prices go, this is about run of the mlil. Not a hit it out of the ballpark, but also not a strike out like many of you here are saying.
Edit: I do have the feeling that the range extender is a sort of last-minute solution. They had hoped for greater mileage, and didn't achieve it. So, they did what rivian and others have done, and just made a way to plug in an extra battery pack. I wouldn't even be surprised if it, in fact, plugged into the 220 volt connector at the back. Although it would make more sense to have its own connection. So, in that sense, there's the chance that this solution will simply disappear after a while, as they get to larger, more efficient, battery packs.