I learned electronics in the navy. My specialty was inertial navigation. But all my courses helped me be who or "what" I am today.... and I am proud to be a "jack of all trades" master of none! heheh..... anyways..... all that theory will help you with control circuits. Especially defrost boards and zone controls relays and the likes. I agree... you will not be fixing bad boards... Probably like 99.9 percent of all employers want to sell the part. Now... if its his device... he may ask you to look at it. All cruise air systems use a triac on their boards. Knowing how a solid state device works helps in troubleshooting the problem. Also you cant go wrong with electronics in understanding basic electricity. This is what helped me move up in the HVAC service world. All I had to learn more of faster, was refrigeration. Now if only I could remember basic current flow.... LOL
Knowledge is power. In anything you do!