I printed in TPU and it came out well. unfortunately the shape is not suitable for iPhone 11. As this phone has round corners while this case is designed for rectangle corners like may be the iPhone 12 has.
interesting. I'm not sure what you mean by not having rounded corners like the iPhone 11. It does hav that and follows contour of the iPhone 11 corners exactly when printed using PEA. I'm currently using it with an iPhone 11 myself. Maybe an issue with using TPU or some other settings. It is definitely not for the iPhone 12.
The shape from the top view might follow the iPhone 11 but from the side the profile of the 11 is round and the case is straight. I tried to highlight it here in this picture comparing iPhone 11 vs 12. This case fits an iPhone 12 perfectly which has exactly the same size and dimensions as the 11 but a straight profile rather than the round profile of the 11.
Here is an actual case (yellow) for the iPhone 11 and you can clearly see the round profile compared to the straight profile (black) of your design. https://makerworld.com/models/58377
I had layer adhesion problems printed in pla. broke at the connection between side walls and back immediately. Everything else was very sturdy and could not have been broken by hand easily.