Ene-reductases (EREDs) efficiently reduce activated C═C bonds, but their activity toward tetra-substituted alkenes has been largely unexplored. Here, we report the first systematic study demonstrating that several EREDs catalyze the stereoselective reduction of tri- and tetra-substituted cyclohexenones while investigating the influence of different cofactors. To enable a scalable application, the best enzyme (YqjM) was co-immobilized with glucose dehydrogenase on Ni–NTA cellulose beads, achieving >99% immobilization efficiency and high operational stability. The immobilized system was successfully scaled to 200 mL, reaching full substrate conversion without enzyme degradation over 9 days.