Sorry to disagree here.
But Fairphone has on more than one occasion explained their way of production/delivery and how they are waiting for a new batch of phones to arrive. While the phones themselves even might be produced in a constant stream, the shipping is organized in larger quantities and therefore unlikely to take place every other day.
Take a look here:
This stays this way until a batch of Fairphone 3’s arrives at our distribution center and we can assign an FP3 to your order.
Try searching for the term “batch” on the Fairphone homepage and you will be presented with lots of results. In my opinion you will hardly find any company, that is more transparent about all the things they are doing and the ways they are going.
While I am myself often are really curious about one thing or the other, I understand as well, that there are limits to being open about everything. Maybe it’s even the fact, that Fairphone is so open about so many things, that one expects them to explain all they do and everything that happens.
Regarding the “back cover woes” you are quite correct.
That’s just speculation on my side. But the fact, that they discontinued the lettering with the FP3+ tells something. I doubt, that this was due to a change in optical preferences.