I’m scheduling January CE for two third-year apprentices and a junior tech, and I want to choose the classes that build judgment, not just rack hours. Our local JATC has an 8-hour backflow tester prep, a 2024 UPC update, and a hydronic troubleshooting lab on Tuesdays 6–9 PM — if you had to pick one first for long-term growth, which would you send them to and why?