I'm using an araree case that is similar to the tough armor slim but much cheaper. Itd recommend it. It's slim, and has a hinge cover https://www.amazon.com/dp/B09B96TXSL?ref=ppx_pop_mob_ap_share

https://www.amazon.com/araree-Stylish-Compatible-Samsung-Protective/dp/B09B96TXSL/ref=mp_s_a_1_3?dchild=1&keywords=araree+z+flip+3+case&qid=1631952630&sr=8-3 has a piece of plastic that covers the hinge. I have a similar one on my Zflip 5,G.

Cases with hinge protection:

https://www.amazon.com/gp/product/B09B96TXSL/ref=ox_sc_act_title_2?smid=A9JPEX3KMXVXW&psc=1

https://www.amazon.com/gp/product/B0939CYGHY/ref=ox_sc_act_title_5?smid=A2SFKRF5TPZMT5&th=1

https://www.amazon.com/gp/product/B09B181BFK/ref=ox_sc_act_title_6?smid=A3DVC6WBVNJ5RS&th=1

https://www.amazon.com/gp/product/B06XB92RWM/ref=ox_sc_act_title_4?smid=A39OFLCM1FUKXS&psc=1