So I don't think it's unethical to work less as long as your employer is still happy with what you do. Sure, lying is always suboptimal. But if your company likes your output and would just be confused by the hours needed to achieve, I don't see a big problem with it. You could even argue that working full time and producing 8x as much could bring coworkers in trouble who already can barely match OPs output. And they will exist, he wouldn't have gotten to the point where he is if he constantly was the worst performer.