Earlier quoted context omitted.
That's not how these calculations work at all. Weight (if it doesn't change the size or shape) really only has an effect on rolling resistance, which is a small portion of overall losses. The extra weight should make a marginal difference in efficiency. Just expect more tire wear.
Doesn’t weight have a massive effect on power needed for acceleration ? To go from A to B You need to get up to speed but also acceleration for regulating your speed after taking a turn, crossing a traffic light, passing someone over…
Though, neglecting air resistance is a huge deal. A cyclist traveling over 20mph is spending something like 90% of their energy at that point overcoming air resistance. For objects travelling faster, it's a square low of how much more power is needed. Air resistance is a very huge effect. With that said, if travel is dominated by accelerating and decelerating (eg: urban or mountainous environments), then yeah - weight is a huge big deal.