From your article: "fuel savings of 3.2 to 5.3%" from rounding of the front
The article itself states there are bigger benefits to be had modifying the trailer:
"Further aerodynamic improvements are possible, notably on the trailer. For example aerodynamic add-ons, such as tails and
side wings, could help deliver even higher significant fuel savings. Their potential is explored in another T&E briefing. [23]"
Here's a study which pretty much confirms my idea of slightly rounding off the nose would be the best thing https://www.transportenvironment.org/wp-content/uploads/2021...
Image here: https://ibb.co/FgZvz6p