Please note, I’m not saying that the engineers are idiots. Sometimes we can all get stuck in one type of thinking that it is hard to think outside the box.
An aluminum battery is not as sustainable in terms of Teslas main goal. But you have to weigh up the use case of lugging around all the extra weight for the bigger battery compared to a single use battery that can be exchanged and doesn’t need coolant or huge weight/volume.
When I bought my standard range model Y everyone asked me how I would cope with having such a limited range. My response is that I rarely do more than 400km in a day.
I would love a range extension in any of our cars as sometimes the long distance journeys are a pain to those that don’t want to compromise.
How many times have I used a supercharger in my ownership? 2-3 times a year.
I also believe that it would be much more complicated an install than just connecting wiring.
If this range extension is ANYTHING like current Tesla battery packs - there needs to be consideration for liquid cooling and a temp sensors and fluid flow sensors and etc.