You are certainly PERMITTED to make a half -baked repair which will not last, save you money, or improve the safety and controllability of your ride. Nobody debates or votes on whether the bearing set (the headset) or the pair of complete bearings should be replaced, versus just loosening what’s stuck. You can play a mind game “hey, I got another morning out if it!”, but you will waste a lot of your spare time going back nd rinsing out the old WD-40 (or worse) every few weeks or days. You could just replace the headset at a quality repair shop, and be set for a number of years if you do periodic overhauls.

There’s no popularity contest or endurance test here, and no points to win if you don’t get it repaired. Just get your bike fixed properly. Sheesh!