There is test-taking software that locks out all other functions during the essay-writing period. Obviously, damn near anything is hackable, but it’s non-trivial, unlike asking ChatGPT to write your essay for you in the style of a B+ high student. There is some concern about students who learn differently or compose less efficiently, but as father to such a student, I’m still getting to the point where I’m not sure what’s left to do other than sandbox “exploitable” graded work in a controlled environment.