This case is for the regular Pixel 8 phone. It is quite sturdy at 2mm thick in most places. The hole on the back is for a little piece of rubber, so the phone doesn't slide around. You can put whatever you like in there.

The little circle bits are just to cut down on weight and plastic just a little bit. Cannot be seen once the phone is in there.

I printed this in PLA, because it is all I have. My printer is in need of a service, so the quality of my print isn't great. I am sure your print will turn out better. I don't know anything about TPU, so if there is any stretch/shrink stuff you need to be aware of, I cannot help you with that. For PLA it is a firm fit.

Creality

Ender 5

No

No

Prints fine without supports