Indeed @blanchsb !
@ritag whenever you are working with Booleans in hard-surface modelling, (whether you are using BoxCutter, HardOps,or other tools or not, you will probably have to do some manual topology cleanup at some point ( to avoid shading issues) and that is mainly a matter of practicing and getting better at it each time (it’s actually a lot of fun, I think, especially if you like ‘puzzles’).