The switch in the front operates both front and back light. That means wiring is there, wouldn't it be fairly easy to add a switch there at the back that would just illuminate the back light?
Jeez, it's simple things like this combined with not illuminated windows buttons on all doors that makes me sigh really hard at these design choices. Such an amazing car, full options and it misses these simple things. My 20 year old volkswagen has all this and even more.....