Maybe something by Eoin Colfer? I havent read his stuff in a decade and a half so maybe it is for too young an audience but I loved Artemis Fowl books and his other works too. If some language and violence isnt a deal breaker, why not the expanse series by James SA Corey? Pretty good light-hard-sci-fi if that makes sense
Orgo 1 and 2 were challenging for sure but nothing like physical chem or biochem 2. Those were the real skill checks