I would focus on changing brainiac difficulty:
It doesn't seem worth wasting time on later notebooks, especially 8-10. Maybe have Viktor reach chase speed after 15 wrong answers (approx). Reduce his anger gain in this difficulty.
Doing this without Albert, you're given double-digit multiplication (forced to use calculator). Have one pair of multiplied numbers per math question, would generate -10 to 10 range. Other three would generate big addition and subtraction numbers. Example: 8*-6-+28-17--25 (Don't know if that's possible to program.)
Can't effectively explore for exam. Have the 11th math notebook spawn after collecting the 10th notebook, but you can't interact with the exam till Viktor starts chasing again (affects all difficulties). The notebook sprite would have a "loading" symbol that prevents interaction, or while interacting too early it would say "Loading exam..." till chase. One of the two.