You've never used divination magic to cheat on tests. You always wanted to be the best, and shortcuts would do more harm than good. Still, you know enough about how it works from other students' whispers and one failed attempt by a student during your time as an undergrad.
While preparing the final in your office, it occurs to you that Gabriel will potentially face this same dilemma if he goes into academia. He could help you prepare better while gaining valuable experience at the same time. The trade-off is that you'd distract him from his own studying and research efforts.
You leave Gabriel be. He's made great strides in his classes this semester, and you don't want to derail that progress.
You've got options about how to handle potential divination cases. You can protect the test using patterns that artificially increase the uncertainty around the test. With the proper choice of pattern applied to every page, the possible outcomes multiply to the point that no divination pattern will recover what the questions are. You understand the theory, but you'd be applying that theory for the first time.
Alternatively, you can dive into the literature about how to disrupt divination efforts. You've not studied divination. You'd have to go through the magical stacks to find a solution. Divination has been well-researched, though, so you'll have plenty of material to look through.
Finally, you can take a more politically minded, low-magic approach: remind the students about the honor code, while seeding your test with trap questions. By changing the wording right before the test, you narrow the window of time when that test exists in its final form. That greatly increases the chance that a student will study the wrong version of the future test.